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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: Dlsnow on September 04, 2012, 04:06:11 PM



Title: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: Dlsnow on September 04, 2012, 04:06:11 PM
current situation - bus is parked in a truck stop - my regular mechanic is coming out tomorrow morning bringing injectors and tools

1. drove bus out to minneapolis from central wisconsin - everything went fine
2. parked for a week
3. left sunday morning (checked fuel, oil, coolant levels - all good)
  a. started bus
  b. noticed a bit more white smoke than normal as it aired up (figured the cool morning 50F was the issue)
4. drove away (noticed more white/grey smoke as pulled out)
5. amount of smoke was increasing and getting darker grey with accelleration
6. thought getting engine up to temp would help - kept driving - smoke continued
7. stopped to re-check oil, coolant levels (engine slowly came to a stop 5 seconds or so - usually it stops pretty quick 2 sec)
  a. oil stick came out dry (oil stick was popped out 1/2in or so)
  b. coolant level was fine
  c. went to get oil to add - rechecked before adding and level was fine (i thought this was weird but never checked the oil level just after running)
8. started back up to get somewhere safer - the smoke got bad enough that i parked at a truck stop
9. handfull of trucker guys came to check out the 8v71 (they love the sound)
  a. junior (trucker) said - you got fuel and oil mixed coming out of the left exhaust manifold union
  b. probably broke an injector tip
  c. said to get a mechanic out there - if thats the issue its an easy fix with the right tools

you can see the fuel/oil pouring out of the union (connection between the left manifold and exhaust)
 I have a video of the fuel/oil spraying out - http://www.youtube.com/watch?v=yXS799Y4-Ek (http://www.youtube.com/watch?v=yXS799Y4-Ek)


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: robertglines1 on September 04, 2012, 05:57:49 PM
no way for oil to get to exhaust--unless you got big trouble!   What is your oil level in pan doing??  You always check oil in your engine off; after it has drained back to pan. Let us know. Yes does sound like it could be injector ,but doesn't explain oil loss. If your mechanic is a 2 stroke guy then you are in good hands. If not ask questions.   re-read post and see you let it drain back down. so good there. One other thing to check is to make sure all you valves are seating/no broken springs or push rods.(happen to me once)  do wish you a economical and quick fix. Glad you are not making oil(level in pan rising) as that is a sign that fuel is getting past rings or fuel line is broken draining into sump.   Those are the simple things.   Bob 


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: luvrbus on September 04, 2012, 07:11:18 PM
You need to tow it to a shop a injector is not going to do you much good the head will need to come off on that side no compression on the one cylinder probably a valve if you are the lucky type

good luck


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: gumpy on September 04, 2012, 07:57:32 PM
current situation - bus is parked in a truck stop - my regular mechanic is coming out tomorrow morning bringing injectors and tools

1. drove bus out to minneapolis from central wisconsin - everything went fine



Where are you?  (where in Minneapolis?)

Do you need local assistance or are you already back in Wisconsin?


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: Scott & Heather on September 04, 2012, 08:21:07 PM
Word! That's some serious fuel coming out of there. Do let us know what it is...


Sent from iPhone via Tapatalk


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: Dlsnow on September 04, 2012, 11:27:25 PM
Im just over the Minnesota Wisconsin border.  LOL no doubt Minesquito my kids are covered in bites.

Im about 150 miles from home.  Im very fortunate to have a flexible "regular" mechanic who agreed to drive out here with his tools and parts tomorrow morning.  He has and still runs old MCI's in his fleet.  I will update as progress is made.


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: Dlsnow on September 05, 2012, 08:54:35 AM
Update
mechanic should be here in 30the min.


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: Dlsnow on September 05, 2012, 10:10:14 AM
Update
The injector tip was broke off.  Dumping fuel.
Had to replace the original c60 with a c65
About to test it out


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: Oonrahnjay on September 05, 2012, 11:44:18 AM
   Update   The injector tip was broke off.  Dumping fuel.   Had to replace the original c60 with a c65    About to test it out 

    I hope that that's fixed it and it was (in BusNut terms) reasonably cheap.   Good luck.


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: challenger440 on September 05, 2012, 07:09:48 PM
Question, was the fuel dumping out at that connection because of back pressure in the muffler or what?  That is a lot of fuel. j


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: John316 on September 05, 2012, 08:24:35 PM
Welcome aboard, DLSnow.

I don't know if you happened to mention what kind of bus you have?

Aaaaannnnnnddddd.....What happened to the bus? Are you rolling? I am guessing so, otherwise you would have been back. Enjoy.

John


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: luvrbus on September 06, 2012, 06:17:39 AM
The question is where did the tip go if he is lucky enough it passed through the exhaust without breaking a valve ,buried in the head or top of the piston he should buy a Powerball for Sat's drawing

good luck 


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: Dlsnow on September 06, 2012, 06:55:09 AM
Update
it was a quick easy fix in the end.  The new injector resolved the issue.
We drove 150 miles or so and it is not smoking anymore.
I wish it was easier to post pictures i have a few.
This is my first breakdown and we are new to busses.
It was luck that the tow guy couldnt tow the bus as my tow hitch is too low.  He was calling a guy with a torch to come torch off the hitch when Junior and a couple of his friends (truckers) came to check out the 8v71.  Junior asked whay was wrong with it.  He tokd me to start it, then smelled the liquid, said its not oil just looks like it cause the fuel is mixing all that carbon in the manifokd.  And told me to get a mechanic out with an injector.

And that was that.  It was alot cheaper than the tow, hitch removal, new hitch would have been.
Im happily down the road.


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: lostagain on September 06, 2012, 06:59:35 AM
Dlsnow,

I am glad it was fixed and you are down the road.

Regarding posting pictures. Put them on Photobucket or similar site. Then it is easy to copy and paste them to a post here, without size restrictions.

JC


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: John316 on September 06, 2012, 07:11:17 AM
Glad that fixed it, and that you are rolling.

Come on over and join us on the MCI hangout. Good group of guys over there too. http://www.mcibustalk.com/bbs/ (http://www.mcibustalk.com/bbs/)

God bless,

John


Title: Re: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: Dlsnow on September 06, 2012, 05:44:46 PM
Im registered on mcibustalk now!

Thanks John and Dave says hi.

Thanks for the support all.


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: Frank @ TX on September 07, 2012, 03:48:44 PM
I thought I knew some stuff about DD 2 strokes.
How can a broken tip from and injector leak all that fuel to the outside?
I would have thought the fuel would leak back down to the crank case or flood the cylinder.
What am I missing.
Thanks
Frank


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: luvrbus on September 07, 2012, 05:23:16 PM
Yes it can Frank kinda like a flooding carburator on a gas engine I never saw one that bad that didn't lock the engine down though.

I still wonder where the tip is that scares me when they bury on a piston and later down the road the edge of the piston turns loose like happen to Mark


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: eagle19952 on September 08, 2012, 09:09:05 AM
sounds like a good time to pull the air box covers...surely DD gave you some of those   :o


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: Slow Rider on September 17, 2012, 09:23:16 AM
Any progress Dave?  Don't leave us hanging?

Frank


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: Dlsnow on September 17, 2012, 10:21:56 AM
Sorry all,
I didnt mean to abandon this post.  My notifications havent been working, noticed the email on my profile isnt right.  Asking for it to be fixed now.

Update
visual inspection on that cylinder showed no trace through the airbox cover.  Mechanic suggested it must have passed through exhaust.  Is that possible, would it fit.  He admitted in all his years running mci's he has never seen this issue.


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: Dlsnow on September 17, 2012, 10:23:08 AM
On the otherhand
i am currently stranded with what seems to be a lack of fuel (prime lost) kind of issue.
About to prime it.


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: Dlsnow on September 27, 2012, 10:04:32 AM
Well - not out of the woods yet - ran with little smoke the last couple weeks - but got white smoke again
i think the injector issue was a symptom of something else
while running i noticed the same leak as last time (raw fuel coming out of exhaust manifold connection to exhaust pipe)
so I popped off the airbox cover on the cylinder that got the new injector and found what is pictured below
12 similar shape and size metal diamond shaped pieces
they look broken from a rod

I looked through the dd v71 manual - engine section and couldnt find anything remotely close to this shape
what are they - where did they come from?
im confused and praying this is a repairable situation
(https://pbs.twimg.com/media/A3z_yzPCAAAQn96.jpg)


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: luvrbus on September 27, 2012, 10:51:26 AM
Parts from the injector,buy a cheap bore scope from HF and look inside at the top of the head it is repairable exchange head and a piston and liner kit I feel for you but I tried to tell you 


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: John316 on September 27, 2012, 11:09:10 AM
DLS, Sorry to hear the bad news. That is not hoped for. Hopefully your mechanic is still close.

Clifford, as I try to tell new comers, you can seriously go to the bank on what you predict. I am amazed every time.


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: luvrbus on September 27, 2012, 02:12:47 PM
If those pieces were laying inside the air box out side the cylinder ports and not inside the cylinder your blower probably came apart


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: Dlsnow on September 27, 2012, 03:48:10 PM
Those parts came out inside of the air box cover. they were stuck in it with all oily goop.  I look inside of the cylinder with a bore scope and didn't find any significant marks or scratches or scuffs.  I am pulling out the injector right now to use the borescope going to look at the top of the piston.  Looking at the exploded view of the C 60and injector I don't see where these particular parts could have come from.

Blower parts...ill check that ... suggestions on isolating blower parts?


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: gus on September 27, 2012, 04:18:57 PM
They sure look like gear teeth to me.


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: Geoff on September 27, 2012, 04:21:41 PM
Okay, I been having to wait 2 minutes to load every page off this website.  Ready to give up.

Looking at the picture of the penny with the broken pieces I say they are liner ports.

Time to pull the head and put a new kit in that hole, if everything else is okay.

--Geoff


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: luvrbus on September 27, 2012, 04:24:28 PM
While you have the injector out run a compression test if you don't have 350 to 400 lbs running at 900 rpm on the test it's time to slip into your coveralls

good luck


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: eagle19952 on September 27, 2012, 08:39:06 PM
liner ports to me to.....but if you want an in-frame ending park it now.


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: Dlsnow on September 27, 2012, 09:10:11 PM
I didnt see any missing parts of the liner.  I assume "liner parts" meaning the area betwern the ports...they dont seem to have that shape and there are enoigh of them that I would have noticed some missing while I was in there with the scope.  I will take another look tomorrow.
Im going to pull the other airbox covers and see if they are in other cylinders.


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: sdc53 on September 27, 2012, 11:40:36 PM
My vote is for cylinder liner ports, too. Some of those chunks appear to have a cylindrical side to them.  Makes me wonder where else they are - in the cylinder itself? Maybe the reason you lost the injector is a chunk went inside the cylinder and destroyed the injector (and probably the exhaust valves too). 
I'd pull as many airbox covers as you can and look for more chunks. It should be immediately apparent if it is port material by comparing what they look like.  Maybe it is from another cylinder?
My mechanic was able to rotate the engine with a breaker bar while I watched for bottom dead center on various cylinders.  I'd take a peek at the cylinder surface thru the ports after the piston has cleared the ports at BDC and see if the cylinder (or piston or rings) is all boogered up.


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: luvrbus on September 28, 2012, 06:44:26 AM
When you lose a tip always try to find that puppy that little piece of metal will do $$$$ in damage,I have to agree with him that looks to be a old injury to me


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: Dlsnow on September 28, 2012, 11:36:13 AM
Kudos to all who identified them as liner parts - I didnt notice the curve since it is so small.
I washed them up and looked at them closer
lengthwise markings on the smoth shiny side - machining on the opposite side and carbon deposit on the other two
I measured with a dial caliper the machined side of one that is installed and it is the same as the machined side of these pieces (.23mm)
BINGO
So i removed all airboxes and inspected the contents -
so far the 12 pieces came from the left rear cylinder
found one more identicle piece in the right rear
the middle four cylinders (airbox contents) were empty - no metal at least
the left front had a twisted up round wire (see picture below)
so i Barred the engine (rh) to BDC for the rearmost cylinders
 - smooth
 - no scoring
ran the pistons up a bit
 - groove is visible on rings
 - no scoring on pistons
Is it logical to check all of the cylinder liners, pistons?

Also it seems like if one of my liners was effectively broke in two parts i would be able to hear it or it would be locked up (just seems like that to me).

After putting the injector back in yesterday I made a critical mistake - not plugging that oil passage right next to the bolt and washer holding the rack down.
The washer fit right down there
So now im off to spend another hour trying to fish that out - thank God they stick to magnets


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: luvrbus on September 28, 2012, 11:58:34 AM
You are beating your head against a wall test each cylinder for compression it only takes a small nick in one of 4 valves per cylinder for that cylinder to be weak on compression but we all do it different that tip went somewhere 

good luck


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: B_K on September 28, 2012, 01:50:24 PM
Dave trust us on this. If "YODA" aka Clifford or Luvrbus tells you something about one of these ol' relics he knows what he's telling you!

I may only be a "newbie" with slower than dial up connection here lately.
But in a former life here on BCM I was better known as Busted Knuckle and can assure you that of all the advice Luvrbus has ever given, I can count on one hand how many times his info has been incorrect! (and still have 4 fingers and a thumb left over!)

Clifford knows two strokes better than anyone I've ever known. And he knows much about other things too!

So save yourself some time $ & grief and follow his advice. He won't tell ya how to do bargain buster projects. But when he tells you how to do it, it will be RIGHT and you won't have to do it over!

Best of luck.
;D  BK  ;D


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: John316 on September 28, 2012, 02:08:31 PM
Once again, DLS, if Clifford tells you something, you can go to the bank on it. If he says you should test each one, then you should....But, it is your bus. It wouldn't surprise me though, if you don't, that it would cost you way more serious $$$.

Just a thought.


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: Dlsnow on September 28, 2012, 04:39:26 PM
well that is a piece of the puzzle
I knew that Cliff loves crabcakes, knows 2 strokes and is dead on with advice
I didnt know that Cliff was luvrbus (im sure I missed this during orientation)

Recovered the washer - still havent found the injector tip - wasnt in any airboxes, didnt find it in the cylinder that it came from with the bore scope or the cylinder on the other side

I am trying everything that you all suggest and the issue keeps getting more and more isolated - thanks to all
Cliff - I would love to check the compression but lack the required equipment

Mechanic will be on the bus Monday for compression test and whatever that may lead to.

and again thanks to all - I cannot express my appreciation enough
sorry I didnt know your username Cliff


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: rampeyboy on September 30, 2012, 04:48:47 AM
Could they be broken piston ring pieces?


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: Dlsnow on September 30, 2012, 02:10:42 PM
Ok confirming for all.  The pieces were definately liner pieces.

Cliff I will definately get the compression tested...I planned on having the local machanic who runs older mci busses do it.  He has been great so far but when i told him i wanted the compression teated he said i dont know 2stroke dieseld (i dont, just learning) and that he wouldnt because they make so much psi that itll knkck you over.  He said about 2200psi.  I didnt challenge him (i know spec says 565psi new and 515 min from manual) over 350 is what im hoping.

So now i need a mechanic who knows 2stroke detroits in central Wisconsin.

I ordered the HF kit for testing compression.  Looks like you replace the inje tor with the plug from the kit.

Is there a way to do this without a tachometer?

Also...WOW the post reply page popped up in record speed. 


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: Dave5Cs on September 30, 2012, 02:43:21 PM
Clifford , Were me, I'd put in for for a few more Crab Cakes dude.
As usual you were correct and I'm guessing will be fully right by the time DLS is done with this.
Go for the Clams and bellies too, LOL

Dave5Cs ;D 8)


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: sdc53 on September 30, 2012, 05:07:12 PM
Methinks that if the ports were busted to this point that is would equate to broken rings, too because the head of the piston travels below the intake ports.  The rings need a cylindrical surface to slide on and if most of it is gone, the rings would break passing by the large opening.


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: luvrbus on September 30, 2012, 05:36:38 PM
He is headed in the right direction with a compression which is a PITA to preform on those engines if he finds the bad cylinder and maybe more weak ones no sense in wasting his time and money to replace the one bad cylinder just rebuild it a simple solution it will save him money in the long run and it could be just a valve   

He sounds like he can do it if he follows the book


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: Geoff on September 30, 2012, 05:52:44 PM
It might be one hole, it might be that someone overheated the engine and all the kits, heads and injectors are ready to fail.  So the first hole went out-- the rest are ready to follow. With all due respect, the engine may be gone.  That is why you have to follow DD failure analysis prodedure which means you test it when it runs, then start taking it apart to see what the total damage is.

--Geoff


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: Dlsnow on September 30, 2012, 08:01:18 PM
an update is in order - title no longer reflects the progress of this issue - and wanted to save you all from reading all the pages to get up to date
1. not stranded anylonger
  found c60 injector missing "crown" tip - effectively dumping fuel at all times
  replaced with c65
  bus ran alot better - a bit of smoke while running
2. smoke still increases with accelleration
  way less smoke - no longer "obstructing traffic"
  doesnt smoke much until fast idle comes in - and while driving
  used to smoke for about 30 - 60 seconds (depending on temp) as soon as it starts but then clears up
3. discovered the bus is no longer getting up to temp
  used to be just fine - was fine after for couple hundred miles after injector replacement
  found faulty thermostats
  replaced with 170F - DD Powercool 50/50 - flushed it out really good - really good
  bus runs at 180 again :)  -  and stays there (so far) (just tested today - hope it stays good)
4. isolating smoke issue removed airboxes and found liner parts from an apperently "old injury"
  used scope to look in cylinder - liners are in tact and look smooth and shiny
  heads dont look beatup
  still havent found the injector tip :(
5. want to check compression - ordered kit from HF - cant wait

So that is where were at now - thanks for hanging in there with my newbie questions.  I havent worked on a 2 stroke since a kid (repairing 50cc mopeds).  This is alot more metal.  I have the original MCI parts and maintenance manuals as well as the electronic version of the DD v71 manual.  So im working "from the book" on this stuff and with all your help will hopefully I get to the root of this issue.  I would really like to not have to repower this thing.  People say if you take care of these old Detroit 2Strokes they will run forever.

Also the bus draws a croud at truck stops - everyone loves to her the Detroit Diesel roar.

-Dave


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: RickB on October 01, 2012, 07:11:18 AM
Dave,

Where in central Wisconsin are you?

Rick


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: Dlsnow on October 01, 2012, 08:05:01 AM
Wausau area 54403 area code for now...when im through this issue...

Hoping to run to Nashville, Fayettevill AR, Tulsa OK, Dallas TX, Tucson AZ...Quartzsite!

Yes in the bus...


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: luvrbus on October 01, 2012, 07:24:37 PM
You will need 2 flare nuts to plug the return and pressure side when you remove the injector or take a old fuel line and bend it or diesel will be spraying every where 

I hope the HF tester works for you I never saw one used before on a DD mine is a Kent/Moore a little pricey but it works goods you can read the test pressure after the engine has stopped it locks in on the highest reading


good luck


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: RickB on October 02, 2012, 06:48:04 AM
Clifford, isn't the motor supposed to be at operating temperature as well when checking compression?

RB


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: Dlsnow on October 04, 2012, 05:12:45 AM
I connected fuel line from the supply and return inlet on the head.  The great news is that this stop the smoke almost immediately and there's no more fuel dripping out of the manifold.  So I believe this issue is isolated to that specific cylinder and probably the fuel injector or compression.
 Good question Rick. Does the engine me to be up to temperature in order to test the compression?
 I am currently waiting on the compression tester to show up in the mail Tuesday next week.
 Is there any way for me to test this fuel injector?  I checked it and it is not missing the tip like the previous 1 that was in this hole that malfunctioned.


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: bevans6 on October 04, 2012, 06:01:47 AM
The way I understand the compression test for the Detroit is that the engine has to be running during the test.  So it will probably be warm at least.


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: Dlsnow on October 05, 2012, 09:04:46 AM
It was too hard to watch the bus just sit out there not making any progress while I waited up my compression tester to arrive.  So I decided to take the fuel injector to a fuel injector shop to have it tested.  They didn't have to test it to see that it was cracked. They said it would pretty much be just dumping fuel right into the cylinder at all times.  They also had the correct c60 injector available.  So I have the new c60 injector and am reluctant to put it in.  I dont want to break it.

I bore scoped the cylinder again and the liner looks shiny and has no scoring or dull spots.  I dont see any marks on the head and the piston top does t have marks.

One thing i noticed when the c65 injector was being installed is my mechanic didnt measure or adjust the distance from the base to the top of the spring.  Forgive me not knowing the right terminology.  I thought you needed to use a dial caliper to ensure the timing was the same as the others.


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: Oonrahnjay on October 05, 2012, 11:51:33 AM
  It was too hard to watch the bus just sit out there not making any progress while I waited up my compression tester to arrive. (snip) 

     I don't have an engine like yours so I've only been following this on theory so sorry if this is wrong, but it appears to me that you have two problems -- 1) an injector issue, and 2) a mechanical engine damage issue -- both of which could result in total engine damage to your engine if not repaired. 

     This sounds as if you've fixed your injector issue (I hope that the problem that this fixed was the only injector issue you had) but I would be *very* careful about running that engine until I'd found out where those broken pieces came from and I would be sure that I wasn't further damaging the engine by running the engine to "test" the injector.

     Again, sorry if I've missed something, but it appears to me that your engine could be very susceptible to further damage.   BH  NC   USA


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: luvrbus on October 05, 2012, 02:28:50 PM
His damage is done the tip probably took a valve out on exit, Disnow I am having a few doubts about your mechanic lol buy your the correct timing pin a dial indicator will work but is a pain 

You don't just match a injector timing to another injector do those all the same buy yourself a 20 dollar timing pin ,when you loose a tip they blow black smoke like crazy not the grey smoke that comes from fuel with no compression that cylinder is burning no fuel


good luck


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: Dlsnow on October 05, 2012, 05:56:11 PM
Right-Makes more sense to blow black if it is dumping fuel althlugh this started at the same time as my thermostats got stuck and the bus wouldnt get up to temp.  New stats and it gets up to good now.  Not sire if this is a factor.

Ill wait on installing the new injector until after i test the compresion.

Im done with the mechanic after seeing what a healthy injector looks like.  The one he put in didnt have a nipple on it and probably didnt work from the get go.

Question on the injector tool...I see two kent moore options...should i get the one for n60 with 1.460


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: RickB on October 06, 2012, 09:15:24 AM
Just a thought here... Is there any chance these metal pieces were from a previous issue that someone could've missed?

Rick


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: eagle19952 on October 06, 2012, 09:49:47 AM
Just a thought here... Is there any chance these metal pieces were from a previous issue that someone could've missed?

Rick

Lets hope not.


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: Dlsnow on October 06, 2012, 01:37:48 PM
the pieces were definitely liner port parts and were part of an old injury. 
they measure the same width and have the right markings - confirmed liner port parts
I checked each cylinder with scope through the airbox's to confirm all of the current liners are in tact - and all are - all have a nice glaze, all pistons rings have a visible groove - no scoring...
I am certainly no diesel mechanic and this is the only diesel engine I have worked on (full disclosure) - so when I bought the bus I had a reputable DD mechanic look it over (worried he would say it was junk) he said it (the engine) was in good shape and had been well maintained (as least since last rebuild) but he didnt know coaches at all.
So fast forward to now -
  Im waiting on the compression tool - tuesday arrival
  trying to figure what to time this new injector at - 1.460 or 1.470 (manual says 1.460 for c60 and also says 1.470 for coaches with c60) - cant find a 1.470 DD timing tool though

What to do now - will there be a difference?
Do i need to time only the injector i have out or all on this side?


Title: Re: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: thomasinnv on October 06, 2012, 01:44:05 PM
To do it right you need to have all injectors matching and run the rack and time all injectors on both sides.

Sent from my PantechP9070 using Tapatalk 2


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: luvrbus on October 06, 2012, 04:54:44 PM
My favorite pin is the 1.466 for your engine dozens of pins will work it depends on what you want from the engine


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: Dlsnow on October 06, 2012, 06:46:50 PM
What I want from the engine
 - drive all over the country (WI, MI, CA, AZ, NM, CA, FL, AR, OK, TX)
 - be able to run from boulder to san jose over all those passes - is this a bit optimistic?
 - Is it ok to install this injector (after compression test - if over 350psi) and get to my next destination (Fayetteville, AR) before adjusting timing or running the rack?

I have heard "running the rack" is an art and a science
 - I do have the manuals and am able to follow specific directions
 - I also recognize art is difficult to document
 - is this a follow the directions job


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: luvrbus on October 06, 2012, 07:16:56 PM
Just think of that 8v71 as 2 separate 4-71's if both sides are not in harmony you have one side doing all the work not good, the exhaust temperature should be the same on both sides if not start over from the beginning not skipping any of the sequence 

Follow the book you will get it in couple of try's you could not be any worse off doing it yourself than the guy you hired to replace the injector I think I would ask for refund on that deal

 


Title: Re: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: thomasinnv on October 06, 2012, 11:30:07 PM
Like Clifford said if everything is not properly adjusted so that all the cylinders  are doing an equal amount of work you could have problems depending on how far out of balance they are. So the short answer to your question is NO, don't just slap in an injector and finish the job somewhere else down the road. Running the rack and timing the injectors is really not that tough, just take your time and don't be in a hurry and you can do it.

Sent from my PantechP9070 using Tapatalk 2


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: luvrbus on October 07, 2012, 08:40:12 AM
Look at the fuel rods (they work the injectors) and tell us do they have 2 screws or 1 screw for adjustment,I changed Derrick's over to the spring loaded 1 screw to make life a little easier for him the 2 screws adjustments take a little more patience to adjust


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: TomC on October 07, 2012, 09:16:14 AM
Ideally, you want the injectors to be balanced on acceleration. Taking a heat reading on the exhaust right after a hard run is the best.  If the injectors are adjusted properly with exhaust heat the same on all cylinders, whether or not the idle is smooth isn't important.

If you're ever out in Bakersfield, Ca, you should have Don Fairchild do your tune up.  He is a wizard and will squeeze the last drop out of your injection, and will tighten your Jake to the point that it really works well.  When I come down the 5 mile 6% northbound grade of the Grape Vine (I-5) pulling my car, I weigh in at 34,750lbs.  I have to switch between 1 and 2 heads so not to slow down to much with the Jake.  Good Luck, TomC


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: Dlsnow on October 07, 2012, 06:39:29 PM
The fuel injector rocker looks just like the book.  Rocker, lock nut, pushrod with square section for adjustment.

Ok-so my plan is as follows (thursday)
1. Set dial caliper to 1.466 and lock the slide (couldnt get the tool here fast enough)
2. Bar engine over till exhaust valves are full open
3. Check and adjust fuel rocker height until distance from base to top is 1.466
4. Secure lock nut while holding pushrod
5. Recheck height adjust again if necessary
6. Do all of them like above
7. Install new.injector
8. Set height as above
9. Start and verify it still runs
10. Run it on the expressway to get it up to temp
11. Use gun on exhaust to verify left and right temps are similar (post results)

Thanks guys...cant wait for the compression tool to arrive.  Hoping to not have bigger problems in this cylinder.


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: lostagain on October 07, 2012, 08:46:28 PM
Do you have the DD service manual for your engine? Just follow the tune up procedure to the letter. Not really hard to do if you have any mechanical sense. You can do it over again if not quite right.

JC


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: luvrbus on October 08, 2012, 07:28:57 AM
I take it you don't have Jake's ?


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: Dlsnow on October 08, 2012, 11:17:18 AM
No jakes...yet
With luck ill get the bus down to nashville then out to tucson then on my way to berkley stop in bakersfield to visit the Wizzard (who reportedly has some jakes for sale).
I have heard some say it needs jakes to get down the mountain, others say go slow up (like theres an option) and ride the transmission down.
I am sure someone can point me to a place to get jakes before bakersfield.


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: lostagain on October 08, 2012, 12:13:41 PM
Dlsnow, you can drive without Jakes untill you get to Don's. He can install them and adjust them like nobody else.

Going downhill without them, you have to be in a lower gear so that the engine will hold your speed steady so you don't have to use your brakes. Light applications of the brakes is OK, but if the gear is too high and you are using the brakes too much, they will get hot really quickly and fade. You have to have the engine hold you back so you can keep your brakes cool to use if you have to, like for the stop sign at the bottom, LOL. Jakes are nice to have, but all they do is allow you to use a higher gear to go down the hill faster. Start going down from the top with your four way flashers on, in first gear. If that is too slow, you can up-shift into second. A lot easier than finding out you are going too fast and having to apply the brakes hard to slow down enough to down-shift. Of course, you will not over-rev the engine through all this. Keep it below 2200 rpm.

JC


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: luvrbus on October 08, 2012, 12:22:50 PM
You will be in 3rd or 2nd gear anyway or you better be when in the 4th gear on a standard with a 3:73 gear don't put much faith in Jakes slowing you down it is not going to happen I don't care if my buddy Don adjusted the Jakes or not lol


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: eagle19952 on October 08, 2012, 03:22:19 PM
here's a tip you might consider....
When I do injector timing with the proper tool, I have found that it is easier to feel and visualize the equality of the adjustments if you put a few drops of oil on the injector surface, then when you twirl the tool you can feel and visual the "wipe", if it takes all the oil or leaves a "film" or a thicker amount.As long as they are the same (IMO) a .001 diff won't matter. again IMO>)
Conversely, using your dial caliper (which I have never done/had to do) I would think about setting the dial to 1.464 and then using a .002 feeler  gage under the slide. You might get a more uniform adj.
squaring the caliper perpendicular to the injector tappet and gaging off the pin deckboss might not be easy w/o the feeler gage below...
Having the feeler/caliper set to your adj is a good temporary adj....but I would find the tool.


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: Dlsnow on October 09, 2012, 08:20:58 AM
So the seven cylinders with injectors in them are all set to 1.460 (on the hair).  Not sire who the PO had work on thia last but it seems perfect.  I dont want to change it as i dont think ill get as uniform a setup with a caliper. 

Hoping the compression test goes well.

While testing compression i will have to let the engine run a while. To get up to temp. 

Compression test (please correct me where im off)
1 install compression injectir adapter and holdown assembly
2 place line from fuel shpply to return
2 secure rockers and replace fuel rack arm and cover and hose and oil neck
3 startup and get engine up to temp...drive it around till 180 deg
4 shutdown
5 remove cover connect compression dial
6 start engine and set to fast idle
7 read compression dial (pray for 350+)

Im not going to hurt anything running only 7 cylinders (off balance?)


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: eagle19952 on October 09, 2012, 10:31:51 AM
were i you..

1 startup and get engine up to temp...drive it around till 180 deg
2 shutdown
WORK FAST.
3 install compression injectir adapter and holdown assembly
4 place line from fuel supply to return
5 secure rockers and replace fuel rack arm and cover and hose and oil neck
6 start engine and set to fast idle
7 read compression dial (pray for 350+)
8 shutdown


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: Geoff on October 09, 2012, 04:09:19 PM
I don't know where this 350# compression came from, but an "N" piston (non-turbo) needs 500 psi compression, that is on startup, and that is the minimum-- 550# for a new or rebuilt engine. 

--Geoff


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: luvrbus on October 09, 2012, 07:09:30 PM
Use the starter they will go 350# then at 900 rpm they should be 500 ,I have friend with N/A 8v71 in a Eagle that Diesel Exchange installed for him the best it would ever do is 450# on any cylinder it was a bear to start in cold weather but ran good with normal power come to find out they used 17:1 pistons


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: Geoff on October 10, 2012, 09:24:14 AM
I got my DD Field Service manual out and looked at compression readings for a V-71 N engine:

Compression is taken with engine running.

Compression at sea level 600 rpm 565 psi for a new engine, Minimum for a used engine is 515 at 600 rpm.

For a turbo engine with the lower compression pistons the readings are 475 and 425, respectively.

I know from personal experience and many compression tests that once you get at or below 500 psi at idle the "N" Detroit engine gets hard to start.

--Geoff


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: luvrbus on October 10, 2012, 06:34:57 PM
They won't go 500 lbs at 2500ft I know that much lol


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: Dlsnow on October 11, 2012, 07:14:11 AM
Well...as usual...life happens...
compression test kit shows up...
pouring rain and I cant work on the bus
Cant wait for this weekend.

FWIW my experience starting is
50 deg or higher and the bus starts right up (3 or 4 seconds on starter) especially if it was run the last day...rough idles for 10 seconds then smooths out
40 and it is usually 3 reps of 6-10 seconds...rough idles for a minute then smooth

PO said he has had only straight 40 for oil and convinced me the same...only straight 40


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: B_K on October 11, 2012, 08:47:38 AM
Dave there is a solution for working on buses outside in the rain, snow, extreme sun/heat.

I use an "EZ Up" Awning. I use it here outside the shop, & I take it with me on road service calls. Just put it up next to the bus where your going to be working and walla you have a "carport" to work under.
They don't cost that much and fold up nicely for storage and can be used for other uses too!
I think that EVERY BUSNUT should have one.
;D  BK  ;D


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: Dlsnow on October 12, 2012, 05:07:54 AM
Well BK if all goes well i will use the money i saved for a cylinderkit and pickup an EZ-UP


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: luvrbus on October 14, 2012, 09:12:09 AM
You have been quite for a few days any updates ?


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: Geoff on October 14, 2012, 06:20:53 PM
The Harbor Frieght diesel compression tester does not have a dummy injector for a a 2-stroke Detroit.

--Geoff


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: luvrbus on October 14, 2012, 07:45:15 PM
Geoff, I have been wondering how he was going to make it work 

The only thing I like about some 53 series (military) is they have glow plugs and you can remove the glow plugs and use about any type compression gauge


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: Dlsnow on October 14, 2012, 08:46:27 PM
Well - compression seems to check out - the HF kit is the 14 piece one http://www.harborfreight.com/14-piece-diesel-compression-tester-set-46800.html (http://www.harborfreight.com/14-piece-diesel-compression-tester-set-46800.html) and it does have an adapter that is shaped like a v71 injector - followed BK's advice on WORK FAST (note don't burn the #*&$ out of your arms on the exhaust).

Compression was jumping around 300 - 330 with engine warmish (~160) and at fast idle
but...I found the injector wasnt really seated good - reseated and got a solid 480 - engine was cooling though - thinking cooler engine will get higher compression (is this logical?)
the compression gauge is filled with a thick fluid slowing its descent and letting me get a reading - not as nice as the ones with a "max reading" dial but workable.

I want to test it again as I broke rule 1 - Dont be in a hurry (visiting friends from out of town) and I think I can get the cover off faster now with a 12 point socket (was previously using a wrench - took forever to remove rocker covers).

here is the adapter pic -
(https://pbs.twimg.com/media/A5N6tZsCIAAQHvv.jpg:large)

So I checked the airboxes - no more parts showing up in there - scoped the cylinder again - still clean

installed new injector and reassembled -
no more smoke and a whole lot more power
hapilly moving down the road to tulsa OK - any busnuts in/around Tulsa?

heres the compression gauge pic
(https://pbs.twimg.com/media/A5N4zLcCYAEhgF4.jpg:large)


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: luvrbus on October 14, 2012, 09:13:37 PM
Not a bad looking kit for 119 bucks my Kent/Moore was a little more than that, a lot more lol good luck on your travels


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: Dlsnow on October 14, 2012, 09:24:55 PM
one issue I have is the tach reading - I dont have a tachometer
im not sure what my fast idle is set to either
but I assume with the compression reading I have in that hole I dont have valve issues
bus is running remarkably well

I will temp gun the exhaust to see if those readings are the same on each pair of cylinders after my run tomorrow
other than the new injector I didnt adjust the injector rocker as they all checked at 1.460


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: eagle19952 on October 15, 2012, 11:18:50 AM

it does have an adapter that is shaped like a v71 injector - followed BK's advice on WORK FAST  (note don't burn the #*&$ out of your arms on the exhaust).

THAT WOULD HAVE BEEN CHOPPED LIVER'S <----who would be me>
WORDS OF ENCOURAGEMENT, BK SUGGESTED YOU TO BUY A TENT.


were i you..
1 startup and get engine up to temp...drive it around till 180 deg
2 shutdown
WORK FAST

I am guesssing it takes about 7000 posts before you become visable here.... ;D


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: B_K on October 15, 2012, 12:05:19 PM

it does have an adapter that is shaped like a v71 injector - followed BK's advice on WORK FAST  (note don't burn the #*&$ out of your arms on the exhaust).

THAT WOULD HAVE BEEN CHOPPED LIVER'S <----who would be me>
WORDS OF ENCOURAGEMENT, BK SUGGESTED YOU TO BUY A TENT.


were i you..
1 startup and get engine up to temp...drive it around till 180 deg
2 shutdown
WORK FAST

I am guesssing it takes about 7000 posts before you become visable here.... ;D



You would be correct!

Quote from: eagle19952
I am guesssing it takes about 7000 posts before you become visable here.... ;D

How would I know, I only have 40 posts here    ;)
;D  BK  ;D


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: luvrbus on October 15, 2012, 12:24:50 PM
I think it is all the same 10,000 or 1 post there's no difference fwiw the same was for me I never saw that compression testing from HF it was always a cheaply automotive type but then I don't shop HF either


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: Geoff on October 15, 2012, 05:55:37 PM
That Harbor Freight testing injector looks like one for a Cummins 855.  I'm not sure if you are getting a correct reading, and maybe damaging the copper in your Detroit head when you torque it down into the tube.  I have two Kent-Moore DD 2-stroke injector testers and the dummy injector has the same shape as the 2-stroke injector body.

-Geoff


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: luvrbus on October 15, 2012, 06:36:48 PM
Doesn't look like enough taper for a 855 Geoff it looks identical to the one A&E and NTX Tools sell for the 2 strokes probably not as good of quality the Chinese use a yard stick for measurement  fwiw both of the above are made in the USA and cost around 500 bucks for the set lol


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: Dlsnow on October 15, 2012, 08:40:45 PM
You like scaring me Geoff?  I hope I didnt damage the head.

Bus is driving awesome...up the hills in the ozarks and into northern Oklahoma.  90degrees and pulling up big (not too long) hills in 3rd.  Temp holding at 185/190.

Seems to be running good...probably put about 800 miles on last two days.


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: Dlsnow on October 21, 2012, 05:59:25 PM
Well were about 1800 miles down the road.  So far it hasnt acted up again.  I think i replaced a bad injector with a slightly better (but still broke) injector off the mecganics shelf.  Now qith a new (reman) injector from a shop im good.

Thanks all for the help and input.  Slowly making my way to tucson right now.


Title: Re: MCI7 8v71 stranded grey smoke increasing with accelleration (injector issue?)
Post by: Oonrahnjay on October 22, 2012, 06:14:08 AM
  Well were about 1800 miles down the road.  So far it hasnt acted up again.  (snip) 

     That's good news -- between the leaking fuel and the broken pieces, I was afraid that you were in for some serious repair bills.   Hope it keeps up OK.