Here I am

Intermittent stalling

Attention: TDR Forum Junkies
To the point: Click this link and check out the Front Page News story(ies) where we are tracking the introduction of the 2025 Ram HD trucks.

Thanks, TDR Staff

PRESSURE PLATE FAILURE

4X4 will not disengage

Status
Not open for further replies.
OK guys! Here is a problem that is driving me and the mechanics nuts. It's one of those intermittent things that are very hard to diagnose. First I'll describe what triggers it and then what the symptoms are. The problem occurs more frequently on warmer days. It only appears when restarting a warm engine that has been shut off for 5 to 30 minutes. It usually lasts until you physically turn the ignition switch all the way to off, wait a minute or more and restart. Sometimes you may have to do this a couple times. Sometimes the problem repeats after this but it never goes away unless you shut the switch off and restart.
OK, the problem, sometimes but not always when restarting a warm engine, it will start harder than normal. Anywhere from a couple extra revolutions to continued cranking. When started it usually runs fairly well for the first mile and then starts coughing and stalling like it were running out of fuel. If you release the throttle it will immediately accelerate briskly for 5 - 6 seconds and then stall. (This is not good in heavy traffic!) If you push in the clutch it will red line up to around 4000 rpm and immediately stall. If you continue to let it coast during the coughing and stalling it will continually cycle through that and restarting, like it was getting spurts of fuel. If you let it coast to a stop wait and restart without returning the key to the off position it will continue to cycle as above. I have found that if you turn the key all the way to off, wait a minute or more and restart it will run normally afterward about 70 % of the time.
I have had it to a couple different shops and one has researched a number of others and can not come up with an answer. The problem is it has only done it once while in the hands of a mechanic. So far we have cleaned the injectors, replaced the return line, replaced the return check valve, checked the pump pressure (about 30), checked the shutoff solenoid function, inspected everything multiple times for leaks and found none, replaced the fuel filter twice.
The truck is a 95 and never gave me any trouble until about 6 months ago when this started. I am no expert on diesels and am looking for any suggestions as to what the problem could be and any recommendations. Its driving me nuts!
Tim


------------------
Tim Wafer
 
Tim alias iflyrctoo usually when key is turned off the computer(PCM) will rest itself. The PCM does not control direct running of the engine(or injection pump) but does monitor and controls a few fuctions associated with running accesories on the engine or truck. Which leads into a question are any warning lights coming on when this happens? The PCM mite be storing codes without turning warnings light on. I check with scan tool just to see if any thing comes up.
One thing you mentioned is that it revs to 4000 rpm, I believe the fuel shut down soleniod should kill the engine soon after red line(3000).
In the shop manual every thing dealing with fuel delivery can cause most of your symptons except I can't find any thing on increase of rpms when clutch is disengaged.
Also have you checked your low idle adjustment? Saw in recent post that rpms went down at idle but idle screw(nut) was tight. He loosend the nut and adjusted to correct rpm.
How about your injector pump is totally messed up. Hope not.
Engine timing could be messed up, maybe moving around but I don't know how.
Just a few ideas you can check out.


------------------
Missouri Mule 96 White 4X4 ST club cab,(grey int. ),5 spd, 3. 54 reg dif, 8 ft bed, 1 ft high cheater boards, front and side of bed,Pofile V bug shield,
99 Freight liner FL60 blue Cummins 24v 215 hp, 520 torgue,6 spd 3. 59 no spin rear, 16 ft dry box (white) 19. 5 low profile tires,Weight 11,000, gvw 23000, 11 to 12 mpg
Bill Thomas (Wild Bill)
 
Tim,

Since the injector pump is mechanical on the '95 I don't think it's possible for the PCM to be involved at all for an over rev condition. The fuel solenoid can't possible do this since it just turns fuel off or on to the injector pump. Since the situation repeats it should not be a timing slipped condition. There seem to me to be two possabilities:


1) The governor is acting up. This thing is supposed to shut off fuel at or before the redline (3000 RPM). If it's getting enuff fuel to rev beyond the redline the governor is not cutting off the fuel. Period. Fuel shutoff is not controlled by the solenoid for rev limiting. If it was then fooling around with the governor would not change the rev limit and we see from other posts that you can do that. I can't think of a situation where the governor can act like this and be reset by the ignition switch. You might try killing the engine by manually pulling down the fuel solenoid and leaving the switch on and see if you get the same symptoms as turning off the switch. Note that this is different than just waiting with the key on after it has stalled. It that situation the fuel solenoid is still on. The ignition key off will turn the solenoid off. So pulling the solenoid down by hand will give you a solenoid off situation with the key still on. The pull on circuit for the solenoid will not activate until the key is turned to the start position.


2) Burning lube oil in addition to fuel oil. If it is burning lube oil you might be getting close to a runaway engine event. EXTREMLY bad news!! Since it goes away after shutting down the engine for a while I would think that it is heat sensitive. The hottest thing on the engine that is envolved with oil and intake air is the turbo charger. Are the intercooler pipes oily inside after a high rev event? If a seal is leaking oil into the air stream in the turbo charger after it gets hot you might get these symptoms. Might have a crack or something like that (gasket?) that opens when hot and closes when cool. I think you should find out what is happening here ASAP! It would be a good idea to have a fire extenguisher handy to spray into the air intake to stop a runaway until you get this solved.


That's all that I can think of right now. If I'm all wet it wouldn't be the first time. Please let us know what you find out.


------------------
Joe George
Eureka, CA

'95 2500 CC auto 4X4,Combo EGT/boost guage,custom switch panel,PacBrake,TST #5,BD valve body,Automatic motorhome steps on both sides,Foldacover hard bed cover,Cummins chrome kit,Black steel grill guard,Front hitch receiver
 
Tim, have you tried wiring the fuel shutoff soliniod in the on position & then driving it to see if the problem occurs? Their is relay for the soliniod that may be giving you a problem or it could be the soliniod itself.

------------------
Piers
 
There is no sign of motor oil or any problems with the Turbo. I haven't had to add any oil and the problem has been going on for over 6 months now. For almost a month it seem to disappear and everything was fine. Now its back again. Every tome I take it to the shop it works fine. This is what makes it difficult to diagnose. I let him keep it for a week once and it did it to him once. Problem is he shut it off and restarted it to test it and then it ran fine again. My understanding is there is very little electrical in the critical system other that the fuel solenoid. I have just recently learned how that supposedly functions and am fooling with it myself but so far can't see any malfunction related to it. He has checked it too. I am calling the Chrysler rep tomorrow, as he is a friend of a friend of mine and see if he has any ideas. The mechanic has talked to people at Cummings but I might give them a call myself too.
The runaway part of the problem seems to only last about five seconds after releasing the throttle. It then stalls. This only occurs when the engine seems to be stumbling and doesn't matter if the clutch is in or not. Could this be due to air somehow getting into the system? Its beginning to sound more and more like major problems with the injector pump to me. Last weekend it acted up the worst it ever has but all the rest of the week it's been fine. Maybe shutting the key off really has nothing to do with the problem but it sure is funny that it's never stopped unless I do.
I'll fool some more with the solenoid. Any other ideas?
Tim


------------------
Tim Wafer
 
Tim,

I don't see how it could be air getting into the system if the fuel hoses are ok. Anyway, that might cause a stumble, but not an over rev. I wonder if a spring might be broken or slipped out of place in the governor. Could be something in the governor that is sticking so the fuel is shut off completely and then breaks loose long enuff to over fuel it for a little bit. The over reving makes me think it can't be the solenoid. You might take Pier's suggestion and wire it on just to eliminate it for sure. Kind of a PITA to turn off, but at least you will know.


Maybe Power Wagon has an idea. He's the expert on this stuff.
 
Tim , First time around I missed this in the book. Deffective injection pump or misadjusted pump timing can cause starting problems or prevent engine from revving, engine surge at idle ... incorect idle or maximum speed( left out a few).
Also issue 26, page 10, 2nd paragraph. Stalling engine, fix - clean corroded connector under top radiator hose. Wires went to engine speed sensor. Which sends signals to PCM, The PCM then sends them to the Tachometer. This member had an auto matic also so at least some wires went to TPS. I look for loose or corroded connections, you mite have a partially broken wire to the fuel shut off solenoid, or some sensor.
Since it only does it some times seems to me its electical or theirs dirt in the fuel system.
Hope you can find the cure.
 
I've been asked if this problem has been solved. The answer is no! I have just talked to the local Chrysler rep and he wants me to take it to a dealer about 50-60 miles away. They supposedly have a "Cummings expert" there. He said if I take it there that he would write it up under warranty! It's certainly worth the trip and I'm taking it next week. Also the local mechanic took it over to a local college where they were teaching a class in diesel repair. They had a couple guys from Cummings there and they had different opinions on the problem. Most agree it is something in the injector pump but some do not. I just want it fixed, whatever it is. My fear is that I will take it to this other dealer and it will run fine for him while its there. That seems to be the sop.
Tim
 
Iflyrctoo. .

Hey I hope the Cummins tech can help you out but maybe you should see a Bosch tech, they made the pump and would probably have some idea...

------------------
Real BOMBers never get speeding tickets. . just a lot of warnings!
 
does anyone think recall #875 (i think that's the no. ) could be tied into this? it did state that stalling could occur - or am i way off?
 
46mech,

The thing to note here is that it sometimes over revs. An electrical problem can't cause that. I agree with illflem, something is probably haywire in the injection pump.
 
Status
Not open for further replies.
Back
Top