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Discussion Starter #1
94 6.5 diesel K3500 died going down the road. Will not restart.

It died like it was a PMD issue. But never restarted like a PMD normally would.

Lift pump is working good.

The fuel shut off solenoid is working

Fuel filter is changed. Looked dirty but it still had good flow from the T/drain valve and the filter bleeder.

The injector pump return line did not seem like it had as much flow as it should,
Is it possible to back flow into the IP?

The PMD's are good. I tried different "known to be good PMD's and extension harnesses. No change = no start.

It is obviously NOT getting fuel. No smoke, no nothing.

The glow plugs are cycling normally.

I used to have a sheet on how to test the PMD. I seem to have lost it. Does anybody have a good checklist for the PMD?

I am going to double check the Injection Pump return line tomorrow.

Any other thoughts would be enormously appreciated.

Checked grounds and fuses - all good

If anybody is interested, I would pay for a house call. Near L'Erable, Illinois

I'm stumped
 

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R.I.P. Sam
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My post didn't come trough last night.

Did you check any ignition fuses to see if by some fluke, that was the issue?

I looked in the FAQ's for a diagnostic and there wasn't one, so I will add this. Thanks Racer
 
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Failed FSOS maybe?
Check engine harnas and connectors back at the fire wall.
Do you still have the OS filter in there? if yes ,remove it and plug the wire conector back in the OS and try start.
Also try starting with the CTS disconnected.
Check for power at the FSOS leads.
 
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Discussion Starter #6
IP return line is open and flowing. No start with the line disconnected and plenty of fuel coming out the return line.

I haven't checked the OS Filter yet. I think it was removed previously

There is absolutely no smoke at the pipe when cranking.

The glow plug light is coming on and everything seems normal til it doesn't start. There have been no previous indications that the truck may be coming down with the flu.

Redoing grounds again now and adding the extra ground wires that I always add. I add grounds from the battery to the battery box to compensate for the cheesy ground that attaches to the passenger fender.
I also add a ground to the frame at the spot by the starter and a ground directly to the stud by the firewall. I've seen that stud lose ground before - several times. Having a ground to that stud directly from the battery eliminates that possibility.
Can't believe I never added the grounds to this vehicle yet.
I also add a ground from the heater blower to the dash bolt inches away. I did that one when I changed the blower.

Does anybody have a link to checking for codes on OBD1 - 1994? It's been so long since I had to do anything like that, that I've forgotten how. IIRC it's a series of flashes and you count the flashes.
 

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R.I.P. Sam
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Jeff my laptop that has GMTD scan on it lost the LED screen this week or I would be able to help...sorry.

A few suggestions that I'm sure you already thought of:
Timing chain? Did you remove the FOS plunger? Maybe add an additional ground to the PMD cooler plate?
 

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Break an injector line loose and see if there's fuel getting to the injector. With a good PMD, no OS filter and fuel flow out the IP return line while cranking but none to the injectors that's a pretty good indicator the IP has gone belly up. A remote possibility is a bad Crank Position Sensor but the truck should still run... poorly. ~FH
 
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Discussion Starter #11
Haven't got to cracking the injectors. That was down on my list til I get done with the basics. Even though that is kind of a basic in itself. I am relatively positive there is no fuel there.
If it was the timing chain, would I hear some obnoxious noise when cranking?
What is the easiest way to check for a timing chain issue? That has actually been on my to do list for a year. Have the timing set here.
Worst is, this is our last vehicle. I haven't been able to get much done. The 96 needs ball joints and fuel lines I hope. It's leaking a lot of fuel in the valley. Hoping for fuel lines or FFM and not IP.
The 98 needs a transmission at the least. Not sure how it's going to run. It's been sitting a while. I start it every other day or so. It was running funny when the transmission went out. Don't know if that could be transmission related or not.
The 95 also has a fuel leak. Hoping the same for it as the 96 Suburban.
The Jeep is still in Wisconsin getting the engine installed. Won't have it back til after Christmas.
If anybody knows a good cheap vehicle that we could run til we get something back together, we sure would appreciate a HEADS UP. Something we could run and sell or even keep.

Greg, I never pulled the plunger off the fuel shut off solenoid. I pulled the fuel shut off Solenoid and it retracted with every hit of the key, so I just put it back in. Would I be getting fuel out the IP return If the solenoid was acting up?
Is that what you mean by FOS plunger?

Is it normal or unusual for an injection pump to puke suddenly like that with no prior symptoms?

278,000 miles on the truck I believe.

The fuel cap has been off for the duration. I have had plenty of fuel out the T drain and filter bleeder since I started. Even before I loosened the cap

Does anybody know where the little tiny ground on the 2nd stud in from the back of the engine terminates? It looks like it could be a little sketchy.
I would rout to the termination point if I knew where that was. It heads into the large loom that runs across the firewall and heads towards the drivers side.

Are there any fuses on a 1994 that are not in the fuse box under the dash other than the lift pump fuse on the firewall?
Does the lift pump fuse run anything other than the lift pump? I have the side of that fuse that goes to the lift pump jumpered to run the lift pump fulol time while I'm messing around
 

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Discussion Starter #12
Failed FSOS maybe?
Check engine harnas and connectors back at the fire wall.
Do you still have the OS filter in there? if yes ,remove it and plug the wire conector back in the OS and try start.
Also try starting with the CTS disconnected.
Check for power at the FSOS leads.
CTS = Coolant tempature sensor. It's in the way when you try to loosen the pump bolts.

How much could the CTS have to do with things? The fitting in the housing is broken where it plugs in. It still plugs in, But the lip it fits inside is broke off.

I never really thought that it would have much to do with what was going on.

I do not have one of those around. What is the part number for the CTS?

How does that affect starting? Would it be possible for that to shut down the engine?

I'm assuming by the way it looks it has been broken for a while.
 

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Discussion Starter #13
This is the small ground wire
 

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Thatta there ground wire looks not to healthy with that chitty crimp connector and being in that location.It certainly could be the culprit.
Would be much better to solder an eye on it and put it on the stud with another nut.....Might wanna take that stud out and shine it up and use some copperkote on the treads to make a soild ground.
That ground could be going to the ECM.

Not saying it is the problem but the CPS has been known to cause all kinds of problems.

It is possible that the cam key sheared off which would cause the engine to die just like that without harming the engine.
You can check for that when you remove the oil fill tube from the T-cover and put a socket on the IP nut and try turning the IP over.
If the chain had broke you would still be picking parts off the road and not be having this tread.
 
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Discussion Starter #15 (Edited)
Thatta there ground wire looks not to healthy with that chitty crimp connector and being in that location.It certainly could be the culprit.
Would be much better to solder an eye on it and put it on the stud with another nut.....Might wanna take that stud out and shine it up and use some copperkote on the treads to make a soild ground.
That ground could be going to the ECM.

Not saying it is the problem but the CPS has been known to cause all kinds of problems.

It is possible that the cam key sheared off which would cause the engine to die just like that without harming the engine.
You can check for that when you remove the oil fill tube from the T-cover and put a socket on the IP nut and try turning the IP over.
If the chain had broke you would still be picking parts off the road and not be having this tread.
Enlighten me. When trying to turn the IP over am I wanting it to move or NO?
Any idea on the size of the nut?
I'm guessing that if the key sheared , the nut will turn and if the nut doesn't turn the gear is held by the timing?

Took the OS filter off. Does anybody have a part number for that piece of wiring harness that the OS filter plugged into and is now plugged into the IP?

Looks like I could use a complete wiring kit for everything under the intake. With the exception of the short harness the PMD plugs into. I have a couple of those and that harness looks as though it must have been changed.
 

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Any chance the PMD extension cable failed, as in breaking a wire internally?
 
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Discussion Starter #17
Any chance the PMD extension cable failed, as in breaking a wire internally?
See post #1

I have tried several known to be good and new PMDs and extension cables.
 

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Enlighten me. When trying to turn the IP over am I wanting it to move or NO?
Any idea on the size of the nut?
I'm guessing that if the key sheared , the nut will turn and if the nut doesn't turn the gear is held by the timing?

Took the OS filter off. Does anybody have a part number for that piece of wiring harness that the OS filter plugged into and is now plugged into the IP?

Looks like I could use a complete wiring kit for everything under the intake. With the exception of the short harness the PMD plugs into. I have a couple of those and that harness looks as though it must have been changed.
If the cam gear key is sheared you should be able to turn the IP over without turning the crank,..nut is 3/4" me thinks
 
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See post #1

I have tried several known to be good and new PMDs and extension cables.
Sorry, missed the extension try part.
 

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Discussion Starter #20
Not a problem. You gave excellent advise. A tad late, but excellent none the less.

I'm still scratching my head here.

Anybody want a side job figuring this out?
 
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