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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: chazwood on February 16, 2008, 01:52:55 PM



Title: yikes!!!
Post by: chazwood on February 16, 2008, 01:52:55 PM
I've been working on gutting the bus for a week so for a break I changed the oil today.  Decided to fire it up. Started right up, so I checked everything out and flipped the kill switch.......nothing..... flipped it back and forth ....nothing. Stared at it really hard.....nothing. OK, what am I forgetting?....flipped every switch I could lay my hands on....nothing. Well now what do I do?  Jumped out and threw the battery disconnect...nothing. Ran back to the engine to jerk out the main wire in the distributor...................... ::)
Can't figure out how to kill it....trying to fight down the rising panic. (There is something very primal about that much steel churning with no kill switch.) I Actually thought about leaving it and posting here to find out what to do. Fear will do strange things to your mind. What if it suddenly jumps into gear and takes off....What if it revs up too high and melts down....you get the thought process, right?

.... I am now tasting the panic....Crawled into the now quite larger (since I took out the potty tank) engine compartment and stuck my finger over the end of the tiny open disconnected bathroom fitting that was leaking .....died in a second. Wow!!! No way!! What is up with that, people! They must be explaining this stuff in the manual I don't have yet.

Someone explain the whole "kill the engine concept" to me. Cuz' it kinda seems to me if you were to have compressor failure, you've got no way to kill the beast.   (Maybe that's why all those trucks are always running at the truck stops. 8))



How was your day? :P


Title: Re: yikes!!!
Post by: tekebird on February 16, 2008, 02:01:18 PM
Distributor?  whats that?


Title: Re: yikes!!!
Post by: tekebird on February 16, 2008, 02:11:31 PM
OK I got it now by looking at your past posts.

MC-9

No DFistributor on an MC-9 or any other diesel bus.......as there is no sparkplug

no idea what hole you plugged to shut the bus down.

but a diesel will only shut off by doing one of two things.

1. shutting off fuel
2 shutting off Combustion air.

and most are set up with a electrically controlled air operated Shutoff .....so unless you bus is aired up to a certain pint....it is not going to shut off


Title: Re: yikes!!!
Post by: luvrbus on February 16, 2008, 02:16:04 PM
Chaz, I have a 1/4 in rod welded to the stop on top of the governor so I can push it to kill the engine.You don't know what panic is till you blow the oil filter with no air pressure to shut it off ( been there done that) won't happen again       Good luck


Title: Re: yikes!!!
Post by: chazwood on February 16, 2008, 02:20:09 PM
I disconnected the little plastic air line to the bathroom sink and actually had it in my hands just before I started the bus ...."That will leak a little air" I said to myself, but if you had bet me $1000 bucks it would disable the kill switch, I would have taken it and laughed at you.

P.s. yes, there is no distributor, hence the     ".................... ::)"    in my post. remember the rising panic.


Title: Re: yikes!!!
Post by: chazwood on February 16, 2008, 02:28:42 PM
Chaz, I have a 1/4 in rod welded to the stop on top of the governor so I can push it to kill the engine.You don't know what panic is till you blow the oil filter with no air pressure to shut it off ( been there done that) won't happen any more  Good luck


Hang on there ???..... You got what? welded to what? doing what to what?

I like the part about "won't happen any more" but you got to be more specific for the newbie.


Title: Re: yikes!!!
Post by: tekebird on February 16, 2008, 02:42:42 PM
chaz,

you can manually operate the air operated shutdown seleoid, that is what he is talking about.

I suggest you purchase the manuals for your coach....a few nights perusing them will have you a bit more educated......better to know in advance rather than have an issue then come here after damage is done asking why


Title: Re: yikes!!!
Post by: chazwood on February 16, 2008, 02:53:36 PM
I'm with you on the Manual Plan. Is there more than one I should get for the MC-9? (I assume I have to order it from MCI)


BTW, I'm wondering if warnings about disconecting the bathroom air are covered in the manual. Just a thought. :)


Title: Re: yikes!!!
Post by: dkhersh on February 16, 2008, 03:08:25 PM
Chazwood, 

     I would bet it was just coinsidence that your bus ran long enough to build air up far enough to shut itself down at the time you grabed that hose.  Did you leave everything turned off while you were running around with your hands in the air??? ....lol.... I would like to have been there as I did the exact same thing the day I got in ours for the first time.  ........All just part of the insanity........


Title: Re: yikes!!!
Post by: chazwood on February 16, 2008, 03:22:31 PM
That would be pretty good timing if my finger on the air leak had nothing to do with shutting her down. If you had been there you would have seen a slightly white, getting whiter, white dude, with a blank look on his face. I don't remember if (in all my frantic switch flipping) I left the kill switch on or off.

But I did disconnect the batteries. wouldn't that kill the kill switch?


In either case, waiting around till this engine decides it's good and ready to shut down seems a little backwards to me ...I mean, shouldn't I be the one who decides when and where? (I know my wife would disagree, but come on!), what if as soon as I fired it up I had to shut it down???? "I'm sorry, dude, but I'm not good and ready to shut down yet ...you will have to wait" That's insane.  :o

Can someone post a picture of your rods on your governors... heck ,I'll even take a picture of your rods welded on your mayor or city council member ,as long as it give me a way to kill this thing when I'm ready.

Thanks.


Title: Re: yikes!!!
Post by: gus on February 16, 2008, 03:59:35 PM
I agree with dk. The air built up just as you put your finger over the hole which I assume was for an air line to flush the toilet??

You cannot work the shutoff air switch manually since it is electric/air. You must have air to operate it so I guess iyou could work it without electricity but not without air, but I'm not sure you could even do that. My shutoff has the solenoid and air cylinder connected so there is no access to the air cylinder and I think the whole air cyl operation is internal.


Title: Re: yikes!!!
Post by: Tony LEE on February 16, 2008, 04:01:03 PM
The bathroom valve air supply comes off the same air line that feeds the stop solenoid so all tghe air was leaking out of that open line leaving too little air to operate the stop valve.
Any time you disconnect an air line, you must blank it off.

And yes, you are correct, if the battery is disconnected after the engine starts, the stop circuit won't work either.

ALSO it is a bad idea to disconnect the battery with the engine running because the alternator output can do crazy things.

It is easy to operate the stop lever manually - it is on the rear of the top plate on an 8V71 - but on an MCI requires reaching through the fan belt so needs a bit of care.

I have a bike rack on the back so can't open the rear doors fully - so I have connected a wire to the stop lever and run it to the LH rear side door so I can stop the engine by pulling in the wire. Safer than reaching in past the belts anyway.

Some 8V71 have an electrical solenoid that trips the intake flapper and that will also stop the engine, but best to only operate it at idle except in case of emergency. It wion't operate with the battery disconnected either

If you have a manual transmission then easy to stall the engine by putting it in gear and letting out the clutch against the parking brake.


PS Helps us to know what bus and what engine we are helping you with.


Title: Re: yikes!!!
Post by: chazwood on February 16, 2008, 04:23:02 PM
The bus is an 82 mc-9 with a 6v92, a 740 Allison auto and slightly retarded manual operator.


Title: Re: yikes!!!
Post by: coachconverter on February 16, 2008, 04:30:00 PM
You can always stick your arm through that fast moving main belt and push the shotdown arm (term?) manually.  It looks like a rocker-arm lying on it's side.  The shut down solenoid should push a rod that moves that arm toward the front of bus to shut it down, but the solenoid can get stuck.

WARNING - don't do this with your thumb, use a stick or screwdriver or anything you value less than your hand.  I shut one down with my thumb one time and at that very second the solenoid released and ran the ram through the edge of my thumb.  Got the scar to prove it.  Ever since then, I tend to use sticks and screwdrivers for a lot of tasks like this.

Todd


Title: Re: yikes!!!
Post by: Stan on February 16, 2008, 05:24:40 PM
A couple of comments to clarify some of the posts. Your engine DOES NOT have a combustion air shutdown.
Stopping the engine is accomplished by shutting off fuel to the injectors. On MCI and most other buses this is done by a normally open solenoid valve which sends air to the shut down cylinder. When you turn on your master switch it closes that valve. allowing the engine to start.  If you turn off the master switch and open the valve, nothing will happen if there is not some minimum of air pressure (about 30 PSI) to push on the shut down cylinder.

The shut down cylinder is mounted on top of the governor and pushes on the shut down lever. As pointed out, you can move that lever by hand (carefully). HTH


Title: Re: yikes!!!
Post by: chazwood on February 16, 2008, 05:42:09 PM
well with everyone saying something different I'd not just slightly retarded now I'm severe profound.


Is there a way to kill the engine 1 second after I fire it up? (for when I change the oil and forget to refill with new stuff and look down into my hand a second after I hit the start button and say.... "look.... a drain plug".........) ((as a "for instance"... not that I would ever do that.....))


Title: Re: yikes!!!
Post by: Stan on February 16, 2008, 05:52:46 PM
Yes: Find the shut down lever on the top of the governor and decide what is the easiest way to reach it with your hand. Hold the lever closed and the engine will stop.

Edit: If you don't know what the governor is, order a manual for your engine from Detroit Diesel. The engine is not included in the bus manual.


Title: Re: yikes!!!
Post by: chazwood on February 16, 2008, 06:06:00 PM
I'm on it like soot on a diesel.

Thanks. ;D


Title: Re: yikes!!!
Post by: Lin on February 16, 2008, 06:17:01 PM
It seems that one should, to be prepared, decide how they would manually move the shut off level.  If need be, rig something to do it and keep it handy.


Title: Re: yikes!!!
Post by: dparker on February 16, 2008, 06:37:17 PM
Chaz,

You know you may even be more surprised one day when you are driving your bus (sorry coach) down the road and something happens with your air pressure again --

you may want to find a trucker to give you a 5 min tour around the air brakes ... in this case, specifically  the way spring brakes work on things like big trucks and big buses --

also given your self assessed level of knowledge with this thing staying safe with these buses requires a basic pre-trip and an understanding of automatic slack adjusters (if equipped i missed the model and year of your bus) or how to manually check and adjust your brakes as well as checking and draining the air from the system daily or prior to operating the coach --

i must admit i had the same deal happen to me once when i start my coach -- threw the switch and nothing happen - -then i caught a visual in my head of that little air cylinder on the top of the engine - glanced at the air pressure and thought "hey this thing will not shut down without air pressure" since then if i do something (change oil - filters - anything were i might want to shut the system down quickly -- i use my shop air to get the system to over 110lbs before i start the bus (on my bus it only takes about 25 psi and she will shut down)  -- on my coach (an older mci) it is on the curb side -- side engine compartment -- has a small valve you have to operate once you connect your shop air -- i have since added an aux air compressor that i can operate from the drivers seat -- make it nice to have the bus aired up before starting --

fwiw -- david


Title: Re: yikes!!!
Post by: HighTechRedneck on February 16, 2008, 07:21:17 PM
I'm with you on the Manual Plan. Is there more than one I should get for the MC-9? (I assume I have to order it from MCI)



Coach Information Network is a common source for manuals.

http://www.coachinfo.com/Manuals/Coach/MCI/MCI9.html

Also, note the link on that page for finding engine manuals as well.

Another suggestion towards the point of learning about your bus.  Try to get to the first rally you can.  Even if you can't bring the bus.  You will be able to learn a lot there.  Another thing you might be able to do is find an experienced bus nut in your area.  If you can get together with them for a few hours or a weekend, you can learn a lot.


Title: Re: yikes!!!
Post by: Hartley on February 16, 2008, 08:16:37 PM
Chaz,

Where are you located?

I looked at your profile and got a wierd location that confused mapquest.

I am wondering how far you are away from me? ( Tennessee )

Dave....


Title: Re: yikes!!!
Post by: gumpy on February 16, 2008, 08:55:40 PM
Was laughing my butt off when I read this one. Been there, done that.

As you've probably figured out, your engine did not shut down because it did not have enough air to activate the shutdown solenoid. Whether it was because the toilet line was disconnected or because it had not yet built up enough air is not something I can answer. Either is possible.

I had this same problem once shortly after I bought my first bus. It was a real head scratcher. Then I learned how the system works and where the shutdown components are.  I've since made it a point to start my bus from the rear panel when it's been sitting for more than a few hours. That way, I can watch the oil pressure come up, and be there to shut it down manually.

Here's a photo from an MC8 which shows the shutdown solenoid and lever on an 8v71. It's not exactly the same on a 92 series, but very close. If you look through your fan belts, you'll see it on your engine. Best way for you to understand how it works is to start the bus, let it air up, and then shut it off using the kill switch on the rear remote panel. Watch the solenoid and lever when you hit the switch.

So, if you push that lever with your thumb, it will kill the engine. Be careful, though, as that solenoid can bite you, as has already been pointed out.



Title: Re: yikes!!!
Post by: chazwood on February 16, 2008, 09:28:39 PM
So..... Did we all get a good chuckle in at the newbie chazwoods expense? Come on ....you know you were laughing...heck, half of you admitted you lived through it yourself.

Slapout, Alabama, is officially known as Deatsville for you map quest guys.


If a bus nut lives close by you'd better hurry with the schoolin' ...at the rate I'm messin' up, I will either be dead (and won't need it) or will have lived through it and learned it all. >:( ;D


Title: Re: yikes!!!
Post by: HighTechRedneck on February 16, 2008, 10:04:10 PM
You're in perfect position to come to the Chattanooga rally being planned (assuming you don't blow yourself up first  ;) ).  The date is April 9-14.  The location specifics haven't been finalized yet.  Bubbaqgal is working on the details.

It will be closest and soonest (important for the above mentioned reason  ;) ).

Hope to see you here.

Another way to go would be to go over to Fred Hobe's (http://users.cwnet.com/~thall/fredhobe.htm) in Madison, FL and spend some time with him.

Best yet, go see Fred right away, may save your life.  Then bring you and your bus to the Chattanooga rally for fun and the experience of a bunch of busnuts.




Title: Re: yikes!!!
Post by: buswarrior on February 17, 2008, 01:10:55 AM
Yes, time to put down tools, leave engine turned off, and READ a ton of stuff.

You'd better know about the care and feeding of the air system and brakes on a worn out cast away motorcoach, that you have already been compromising...

There is the right way, and then there are many more of the rest. Unless you can find it in published journals, any advice you get needs to be held with a fair degree of suspicion as to its validity in your situation versus the seat of the soiled pants experience of the story teller.

Bendix has a lovely site with days worth of reading in it on the functionality of the bits and pieces. Many jurisdictions require some formal knowledge of using and testing air brake systems to get your licence, get the training materials.

Like the Kenny Rogers song...You gotta know when to hold 'em.....

happy coaching!
buswarrior


Title: Re: yikes!!!
Post by: Marcus on February 17, 2008, 04:56:36 AM
chaz, I told you I would send you a manual free of charge if you give me your address. It looks like you need a bit more info on the basics before you travel too much. I would be glad to put the manual in the mail for you . Marc


Title: Re: yikes!!!
Post by: gumpy on February 17, 2008, 06:22:25 AM
So..... Did we all get a good chuckle in at the newbie chazwoods expense? Come on ....you know you were laughing...heck, half of you admitted you lived through it yourself.


Absolutely I was laughing. But it was not necessarily at you expense. It was more in fond memories of the fear I experienced the first time it happened to me, and the realization that I had no clue what the heck I was doing, and then the panic attack that came shortly after with the questions of, "What have I gotten myself into?"

craig


Title: Re: yikes!!!
Post by: chazwood on February 17, 2008, 07:14:07 AM
chaz, I told you I would send you a manual free of charge if you give me your address. It looks like you need a bit more info on the basics before you travel too much. I would be glad to put the manual in the mail for you . Marc

I e-mailed you my address that same day. Do you need it again?


Title: Re: yikes!!!
Post by: chazwood on February 17, 2008, 07:18:11 AM
The date is April 9-14. 




April 9-14!!??? How long do you think my luck will hold out? By then I either be a battle scared vet , or six feet under. :P


Title: Re: yikes!!!
Post by: chazwood on February 17, 2008, 07:21:04 AM
So..... Did we all get a good chuckle in at the newbie chazwoods expense? Come on ....you know you were laughing...heck, half of you admitted you lived through it yourself.


Absolutely I was laughing. But it was not necessarily at you expense. It was more in fond memories of the fear I experienced the first time it happened to me, and the realization that I had no clue what the heck I was doing, and then the panic attack that came shortly after with the questions of, "What have I gotten myself into?"

craig


I'm with ya man.  ;D

Say, are you the guy with the grumpy dog website, with the mc9 project? Well never mind. I just saw your address. Before I bought my bus I was reading your website every night till I was cross eyed. After being able to see deep into yours I felt like I knew the mc9 better than any other so I bought one. You do nice work. Very helpful to my own project. I'd be like.... OK....How did he get this seat rail out? Then I'd go to your site and look. Did that a bunch. Very helpful. Can't say enough. Thanks for your help. ;D (so I don't mind if you laugh at me....but the rest of you........... >:(.............. better tighten up........ ;D)


Title: Re: yikes!!!
Post by: HighTechRedneck on February 17, 2008, 07:31:42 AM

April 9-14!!??? How long do you think my luck will hold out? By then I either be a battle scared vet , or six feet under. :P



Yup.  Hence:


Another way to go would be to go over to Fred Hobe's ([url]http://http://users.cwnet.com/~thall/fredhobe.htm[/url]) in Madison, FL and spend some time with him.

Best yet, go see Fred right away, may save your life.  Then bring you and your bus to the Chattanooga rally for fun and the experience of a bunch of busnuts.



Title: Re: yikes!!!
Post by: Sammy on February 17, 2008, 07:43:20 AM
Chaz, ask us ALOT of questions, ask the same ones until you're comfortable with the answers you get.
I will be glad to help you as best as I can, I'm sure other folks will also.
Welcome to the madness, asylum, hobby,money pit,etc. :)
Stop in the chat room in the evenings. Bunch of us are always there bs'ing and ready to help too.
Be careful, stay safe.
Sammy


Title: Re: yikes!!!
Post by: Hi yo silver on February 17, 2008, 10:07:12 AM
OK, just for the sake of learning, I'll ask a dumb question.  Wouldn't the shutdown solenoid work from the power supplied by the alternator, even with the batteries disconnected?  Maybe I'm forgetting something.  (I realize you need the air pressure to actually shut down the engine, as discussed.)  I promise, I'll be the next one you guys will  be laughing at, as soon as I pick up my bus, which I hope to do next week.
Dennis


Title: Re: yikes!!!
Post by: DavidInWilmNC on February 17, 2008, 10:08:02 AM
My MC-8 has a fuel shut of valve down near the fuel filters.  I'm assuming other buses do.  How quickly would this shut down an engine?  I would try it myself, but I don't want to have to deal with re-priming, etc.  For a non-emergency shut down, this might be easier / safer than reaching through that fan belt.  I also like the idea of having some way of shutting it down from the side engine doors like mentioned in a previous post.

I also experienced what you did when I first got my bus.  I wanted to show a friend how it sounded, so I fired it up.  My neighbors (the ones who were complaining about it) came out to their back yard during this time.  I decided to shut it down before they got too bitchy upset.  Guess what... it didn't shut down.  After it built enough air, it did, but by that time I was standing up trying to not look upset (cool, actually) when it suddenly shut down.  My friend asked me why did it shut down like that.  I said, oh, it has to have enough air pressure to shut down, and there's just enough do do that now.  See, I knew why it didn't shut down, but the panic of it not responding immediately kind of caused me to forget.  I now start it up with shop air.  One never knows when there's going to be a need to shut it down in a hurry.

I also had problems with it not starting one day.  It sounded odd when cranking and would blow out one big puff of black smoke.  I posted here and was told to check the emergency shut down, among other things.  No need, I thought, as I had never even played with that switch.  After a few days of dinking around with it, I decided to see what that little lever on top was that looked out of place.  Guess what... it was the emergency shut down flap lever.  I reset it and, bingo, it fired right up!  It smoked like hell for a while, but all was good.  The point is that most of these 'problems' have very simple solutions, ultimately.  Of course, I was thinking about having a bad blower, blown engine, etc.  Get, read, and learn the manuals.  It'll all make more sense and make things less stressful.

David



Title: Re: yikes!!!
Post by: Len Silva on February 17, 2008, 11:16:23 AM
I don't think it's that big of a deal, but if anyone does, then how about installing a small (1 gal or so) air tank, fed through a check valve, and supplying only the shut down solenoid.  It would be much easier to keep it leak free than the whole bus.

FWIW,
Len


Title: Re: yikes!!!
Post by: chazwood on February 17, 2008, 11:56:24 AM
Hello friends.....and the rest of you that were laughing at me....

I went out today and tried the whole scenario over again,(without turning off the battery and without the rising panic 8)) I left the bathroom connection leaking, and after running it on fast idle for a bit, flipped the kill switch. It took a long time to decide to die. I then started back up....plugged the hose....hit the kill and it died instantly. So what I gathered from this little experiment was, if the air pressure is high enough to fast idle (was not, the other day) It will still kill with an air leak, but it hesitates for a while making you think it won't die. Don't know about the battery angle cuz' I left it on. However, and furthermore, having learned the kill-it-with-a-stick-trick, I'm now comfortable that I have the Beast well in hand. (until a few minuets from now, of course.)



Now, wasnt that fun? ;D


Title: Re: yikes!!!
Post by: gus on February 17, 2008, 12:24:13 PM
Stan,

My understanding is that the elect/air valve is normally closed and iis activated to open when the master switch is turned off and, if there is air pressure, the engine will stop.

Once air pressure bleeds off the fuel is again turned on and stays on until air press again builds up. So, after the bus sits a few days the fuel is always on.

My theory, which I've never tried but will, is that the engine will start with the master turned off if there is no air pressure. The reason I think this is that, from experience, I know it won't shut off with no air pressure.

I also know (don't ask me how!) that if the rear shutdown switch is accidentally turned off the engine will start and run fine for a few minutes then die once air pressure builds up!


Title: Re: yikes!!!
Post by: belfert on February 17, 2008, 12:48:25 PM
One good thing about my Series 60 is no air needed to shutdown.  Of course, that expensive DDEC can cause serious pain if it dies.


Title: Re: yikes!!!
Post by: Lin on February 17, 2008, 02:40:31 PM
Gus,
     The engine will start with the master switch off, or at least mine will.  I can start it from the back without turning the switch on.  It will probably shut down when it gets enough air though.


Title: Re: yikes!!!
Post by: Stan on February 17, 2008, 02:42:06 PM
Gus: You are wrong about the solenoid shut down valve. It is a normally open valve. Since the shut down sequence is dependent on air pressure being available, you can disregard anything that happens when there is no air pressure.

A diesel engine will start without air pressure, without batteries and regardless of switch positions if it is cranked, even by turning the crankshaft with a wrench. There are published warnings on how to prevent an engine starting if you have to turn the crankshaft, such as when setting valves.

If the governor is adjusted properly, it will be sitting in the idle position when the engine is stopped unless some mechanical force is holding it in the stopped position. On buses that use the electric/air shutdown, this force is the air coming through the normally open valve and pushing the piston out of the shutdown cylinder mounted on top of the governor. No air pressure, the engine will run!!

To clear up any confusion from other posts, there are two separate components in this system. There is an electrically operated solenoid valve remotely mounted and there is an air cylinder mounted on top of the governor.


Title: Re: yikes!!!
Post by: NewbeeMC9 on February 17, 2008, 04:25:26 PM
I can laff with you too :D

Most of us learn about that solenoid when the rear switch is in in the wrong position and the bus just shut's down unexpectedley,  a diffrent panic.  Luckily i had read about it hear so after calming down figured it out.  But it still doesn't ring as loudly as when it happens to you ;D


Title: Re: yikes!!!
Post by: dparker on February 17, 2008, 05:32:20 PM
Chaz,

I am not aware of the location in Alabama were slapout is ... ?  I live in a little town right across the state line in gerogia -- very close to fort payne, Alabama ... i have 13 CDL hazemat tanker endorsed truck drivers and am a cdl holder as well .. i am converting a mc7, very similar to your coach just older -- if you can give me a location that is a little more familiar perhaps we could get together and i could give what little i know about air brakes and some basics -- happy to help if you want it

by the way, i must admit that i did smile a little -- but only because i had been there -- what made it really funny was that you were willing to admit -

i bet there are a bunch of 12vdc devices burned up when all these nuts attempted to cross convert and intergrate 12volt devices with relays and the 24 vdc coach ... the difference is they come on line and mention how they did this and that but failed to mention that leason came at the price of letting the smoke out of some components -- as you know smoke runs everything on your bus -- you let it and it quits -- so far i have let the smoke out of my 24 vdc voltage regulator --- 3 led 12 volts marking lights (they do not like 24 vdc for very long) ... one trace inverter -- forgot to unhook that "temp" connection.... fuel pump on genset -- forgot that that hot wire was from the coach and not the 12 vdc system -- just try not to let all that smoke out of the 2 stroke detroit --

by the way if you do not think you are getting enough attention on this board just ask everyone what kind of oil to put in your bus ... lol

daivd



Title: Re: yikes!!!
Post by: chazwood on February 17, 2008, 05:49:18 PM
I've always said......what good is a story , if you can't tell it?  ;D

Deatsville is official , "Slapout" to the locals.



Title: Re: yikes!!!
Post by: JohnEd on February 17, 2008, 10:29:24 PM
The Chaz,

Whenever I see your name here I go pop some popcorn( canned corn seems to take forever), open a pepsi, get comfortable and prepare to be entertained.  You never disapoint!  Thanks!  I will never forget "Oh, Look....a crank case oil drain plug".  This is Comedy Central grade stuff, man.

John


Title: Re: yikes!!!
Post by: Tony LEE on February 18, 2008, 12:46:17 AM
"Wouldn't the shutdown solenoid work from the power supplied by the alternator, even with the batteries disconnected? "

In an MCI with belt driven alternator or belt driven AC compressor, the alternator field won't be energised until the air pressure is high enough to tension all the belts correctly.


Title: Re: yikes!!!
Post by: Stan on February 18, 2008, 05:05:37 AM
Quote
"Wouldn't the shutdown solenoid work from the power supplied by the alternator, even with the batteries disconnected? "

All the older buses with the big Delco alternator used an external voltage regulator which has to have some minimum input voltage before they can supply field current to the alternator. No field current = no output voltage.



Title: Re: yikes!!!
Post by: Hi yo silver on February 18, 2008, 07:22:31 AM
Thanks Stan,
Now I get it.  You have solved a mystery.
Dennis


Title: Re: yikes!!!
Post by: gus on February 18, 2008, 08:11:05 PM
Stan,

On my 671 the elect solenoid and air valve are bolted together, there is nothing on the governor.

The only time the air valve is open is when the master switch is turned off - then the solenoid opens the air valve to the air cylinder which shuts off fuel via a rod directly into the cyl head and injectors.

So, the air valve is normally closed as long as there is air pressure.

Lin,

Thanks, you have saved me the trouble of the experiment. I thought that would happen, I couldn't see anything to keep it from starting since the fuel is always on after air pressure is gone.


Title: Re: yikes!!!
Post by: Stan on February 19, 2008, 05:48:04 AM
Gus: A solenoid valve is an integral unit as you describe, a solenoid screwed to the top of a valve body. It requires power to pull the solenoid (A Skinner V5 valve draws 10 watts) so you cannot have a valve under power when the engine is shut down or the batteries will go dead. This is also a failsafe device, in that if you lose electrical power, the engine will stop.

I am not familiar with the shutdown system you describe, but it is the same principle as the one I described. Air, from the normally open shut down valve, pushes the piston out of a cylinder which pushes the injector rack to the stop position. It doesn't really matter where the cylinder is mounted. On the old truck engines it was all manual - a cable up through the cab floor with a knob you pulled to stop the engine.