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Author Topic: AHHHH!!! 1000 miles @ 50mph...and no hill climbing power....HELP!  (Read 3441 times)
Eric
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« on: October 23, 2009, 08:22:31 PM »

HELLO ALL! long time no chat! just finished a nice cross of the country with "Endeavor" all was great except it's gov is 50mph according to my gps and to make things worse on the slightest incline i have no power....i'm dropping down to nearly 35mph climbing the little hills in iowa....any ideas? I don't really mind the 50mph however hill climbing would be great.... no smoke no problems...just no giddyup.. oh yeah the important stuff.. lol Bumping up the MPH to say 60-65 would be great is somebody can help me with this as well!

1985 Neoplan an440 6v92ta with an alison v731
also if it matters current GVW is 29,880lbs

Thanks in advance...!
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Nick Badame Refrig/ACC
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« Reply #1 on: October 23, 2009, 10:32:03 PM »

Hi ekhedge,

Change your fuel filters. They are Clogged!

Good Luck
Nick-
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« Reply #2 on: October 24, 2009, 02:20:55 AM »

Very important-if you've never changed the fuel filters before, make sure you refill the new fuel filters with clean Diesel fuel to the tops before rescrewing them back on so not to loose your fuel prime.  Good Luck, TomC
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« Reply #3 on: October 24, 2009, 04:58:43 AM »

if the filters were pluged , would it not be smoking black from running lean???
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« Reply #4 on: October 24, 2009, 05:04:59 AM »

Check your engine shut down cylinder it is probably not returning keeping the throttle from full open


good luck
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« Reply #5 on: October 24, 2009, 05:38:01 AM »

if the filters were pluged , would it not be smoking black from running lean???

I don't think so.  Black smoke is incomplete combustion of diesel fuel (such as when you open the throttle all the way climbing a hill and engine rpm is slower causing all the fuel to not burn).  Plugged fuel filter will not allow enough fuel to develop power, but what fuel is injected will totally burn (just not enough to create adequate power).  Jack
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« Reply #6 on: October 24, 2009, 06:13:25 AM »

Once you have changed the filters as per previous instructions..if it doesn't work I had problems with a transfer pump not hard to change or real expensive.. Huh
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« Reply #7 on: October 24, 2009, 06:36:11 AM »

As Luvrbus said, the simplest things first.  Make sure you are getting full throttle at the governor.  Install a fuel pressure gauge to check out the fuel system.
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« Reply #8 on: October 24, 2009, 07:09:33 AM »

All of the above but I would check the air filter and housing as well, make sure you have a good filter and no birds nest cutting off your DD's oxygen supply.


RB
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« Reply #9 on: October 24, 2009, 01:30:52 PM »

Happened to me last fall.   No speed or power and no black smoke.   Fuel filters were plugged.
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gus
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« Reply #10 on: October 24, 2009, 01:53:14 PM »

As others have posted this is a classic clogged fuel filter symptom. Mine is showing this so I'm going to do it next week.

I notice it when it takes more throttle to get the same power as before, the engine simply isn't getting as much fuel as it should.

It is usually the primary filter since it is first in line, but if you've never changed/cleaned yours it is way past time.

Fortunately I still have the original primary filter and it just has to be cleaned off, no expensive filter to buy.
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johns4104s
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« Reply #11 on: October 24, 2009, 08:18:02 PM »

Ditto on the air filter and fuel filters, I have twice the power after changing my air filter. Boy was it blocked.

John
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Garymci5
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« Reply #12 on: October 24, 2009, 09:54:13 PM »

I would guess that a '85 bus would run at least 65mph on the govenor....my old '76 Eagle ran 80mph on spec RPM (at least it sounded like it).

Must have fuel and air:

My even older GMC Fishbowl was gov'd to 55mph (under RPM at 1850; DD 6V71), but turned it up and would run an indicated 72mph on oversized tires. Like the old man said "when it sounds like a sewing maching, it's just right". That's about 2400+ RPM. He was right. Ran the same route 4 years, ever year a different change, every year a little faster. Final year ran the same hills at 12mph faster, minimal speed lost from flat cruising. Same load, same weather, same same.

I'd also take a gander and say that with a turbo one could install bigger injectors for a slight bump in power.  If'n it were me a water injection kit would find it's way under the hood, to both keep temps down and to facilitate complete combustion during WOT (starting out or climbing hills).  Would also wrap the exhaust to preserve all the exhaust energy possible. Lost heat is lost power due to lost velocity, THE key factor to turbo performance is velocity.

Also recommend to ensure the exit tract is flowing well. Diesel's flow A LOT of air/CFM. Want to be scientific? Install a back pressure tester. I didn't, but did make a quasi dual exhaust and noticed a difference, besides all the noise. Previously, at WOT, the backpressure was so great, that even at speed, the pressure was great enough to part heavy water on the road at 65mph!..! Holy Sacred Cow Bat Bird!

My last little trick, not sure if it actually helped, was to use ATF for the oil bath filters. It's lighter than engine oil (SAE 30 for a 6V71) and the theory was less resistance equals more flow ='s more power. Never got around to making intact ram air ducts.....

Nowadays one has BioDiesel to help increase Cetane among the many other benefits. The 'race fuel' for compression igntion technology (or lack thereof).

So there you have it.... A full report is expected Monday morning of what was done and scientific results to back up the theories. Shocked Grin
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« Reply #13 on: October 24, 2009, 11:17:25 PM »

EK -

After doing the maintenance that the others have suggested, be aware:

1.  92 series engines do not like running much over 2100 rpm.  71s can, but don't risk it with a 92.

2.  You've got a transit.  Most are set up for 57 - 62 mph max, but really decent 0 - 30 times.  So, the only way to get more top end out of your bus, after having the rack run to make sure the bus is hitting on all six, and that it's governor is set correctly, is to replace the rear axle's ring & pinion pumpkin.  More than likely, you've got a 5:38 gearset in there.  To obtain 70+ mph with the angle drive gearbox, you'll need one of the coveted 4.10:1 gearsets.  Last time somebody here checked, those were special order and would also set you back about $2,000.

FWIW & HTH. . .

 Wink
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« Reply #14 on: October 25, 2009, 07:59:46 AM »

RJ has a good point, transits usually don't have highway gears unless someone has already changed them or it was originally a suburban model.

On the other hand there is still a power problem that must be dealt with first.  If it is having trouble climbing hills with a transit rear end, it would be worse with highway gears.
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Don4107
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« Reply #15 on: October 25, 2009, 09:44:35 AM »

Does it have a boost pressure gauge?  If so what is it running when pulling hard? Does not take much leakage to cause problems.

Good luck
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JohnEd
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« Reply #16 on: October 25, 2009, 03:16:27 PM »

If it had a clogged air filter I think the indication is "black" smoke.  You need a filter minder so you can change the element only when it needs to be change and not at some interval which might be to long or to short.

John
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« Reply #17 on: October 26, 2009, 06:06:15 AM »

If it had a clogged air filter I think the indication is "black" smoke. 
John

John,
    I agree, black smoke is incompolete combustion and you get incomplete combustion if there is not enough oxygen (air) present. 
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« Reply #18 on: October 26, 2009, 08:29:16 AM »

And another thing! 

I was recently working on my old Winnie carb.  Had the air cleaner of and was setting the idle mix.  Got it puring and throbbing nicely and then reinstalled the air cleaner.  When I put the "lid" on the air cleaner my idle dropped a good 150 RPM.  DRAT!  Ever seen one of those "lifetime" cleanable air filters in the parts store on display?  $40 for the one for my 440CID.  It gets washed and oiled to keep it fresh and the air flowing.  I never washed this thing and i had only a hundred miles on it over a couple years time.  I held it up to the light and it had hundreds of small holes in it that i could see thru.  The rest seemed opaque.  If you have one of these "premium" puppies I suggest you look it over closely and do the idle test.

I over filled my oil bath filter once.  And only once.  They become very restrictive when over filled. I learned that the hard way.  Good thing I way overfilled it cause if it had only been slightly overfilled it might have slipped past me and I could have been troubleshoot my lost MPG and HP to the tune of hundreds of dollars till I "discovered"  the problem....I injected.  Oh, well!  Too soon old.

Good luck,

John
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Eric
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« Reply #19 on: October 27, 2009, 01:17:48 PM »

sorry no net right now.....I replaced both fuel filters and put a new air filter in literally 2 days prior to our trip....we don't have a boost gauge for pressure the the stop solnoid actually "jammed on the trip so i removed it and just ran back and shut off the rail for our trip....it's now back on but nothing has improved as far as any giddyup! As far as "turning it up " i would love too but i have no clue the required proccess to do so! all the ideas are appreciated!!! Running the rail sounds good but nobody so far in Northeast ohio is willing to even touch this thing!
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« Reply #20 on: October 28, 2009, 12:33:41 AM »

EK,

I keep coming back to "no fuel".  The clue is that you get no black smoke when you floor her.  Even the best of them smoke if they are in tune.  I would think that you must be starving to get zero smoke.  I installed filters at my tank before the electric aux pump.

If you have bad fuel you might be plugging the filter as soon as you install it.

If your fuel is contaminated with gasoline, just a little, I think it runs poorly.  A friend got a load of gas and he barely limped home with a powerless engine.  Easy test....take of the fuel filler cap and give it a sniff.  It should not even remind you of gas.  Lots of gas and it won't run.  Might be the attendant or the service station tank?Huh

To eliminate anything from the filters back one guy rigged a can of D fuel up to the input of the filters and took the bus for a test ride.  He found that the performance was exceptional and then knew where to look for the problem.  I think he found that the tank outlet was plugged at the fitting.  Always acted like a plugged filter.

Good luck with this.  I know how deeply frustrating this must be when you have run out of things to check.  If it was running well in the recent past I think that would eliminate the rack as the cause.  Me thinks they go down hill gracefully for the most part.

John
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Nick Badame Refrig/ACC
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« Reply #21 on: October 28, 2009, 03:44:22 AM »

Another Idea...

Years ago, my dad had a simular problem in his 4104.

It turned out to be a collapsing Fuel Line.... He replaced the supply line from the tank, to the engine compartment

and sure enough, the problem resolved. After closer inspection of the rubber line, it had collapsed where the line

traveled through the bulkhead.

Good Luck
Nick-
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« Reply #22 on: October 28, 2009, 07:07:31 PM »

I cleaned my primary fuel filter and replaced the secondary 8,000 mi ago.

Much to my surprise the bus started "Clogged Filter" symptoms during my short trip over the past weekend. Sure enough, the primary was clogged again. I was amazed at how dirty it was after so little mileage.

Filters clog especially bad after a bus has been sitting for a few years, I had to change/clean mine three times in only a few thousand miles right after I got it.

My primary filter is the "stacked disk" original type which is cleaned in solvent and the secondary is the replaceable type.
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« Reply #23 on: October 29, 2009, 04:06:42 AM »

Ekhedge, Pioneer trails bus line in Millersburg.Ohio will probably look at your bus . Their mechanic Paul is very good. They are located on state route 241 north of Millersburg. Thanks ,Marc
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Eric
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« Reply #24 on: October 30, 2009, 06:11:01 PM »

I'm Going to Start with Fuel filters then!!! Thanks Everyone! ...I must say thought Nick when your father found the collapsing fuel line that had to take some serious thought!.....And i'll check out the shop in Millersburg! Again thanks everyone!
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