Truck stalls out when running and has trouble starting again.

[Brofer]

:confused:My 95 GMC K2500 6.5 Diesel has a random stalling problem that occurs when running conditions is fine. The engine will not turn over and just keeps crankin. I have replaced the ground to the battery, replaced the battery, and it seems to just quit. And after some wire wiggling and passed time it will fire up and run as smooth as ever. I'm not sure! Anyone have any ideas?

[Chevylover]

:confused:My 95 GMC K2500 6.5 Diesel has a random stalling problem that occurs when running conditions is fine. The engine will not turn over and just keeps crankin. I have replaced the ground to the battery, replaced the battery, and it seems to just quit. And after some wire wiggling and passed time it will fire up and run as smooth as ever. I'm not sure! Anyone have any ideas?


Could be the PMD problem, a bad fuel shutoff solenoid or just a short/broken wire as you mentioned that after some wire wiggling it will fire up again.


Cu,
Sven

[Sundance]

"The engine will not turn over and just keeps crankin."

I am confused here.......... it can't be crankin" if it won't turn over. Do you mean it won't fire while cranking over? And then later it fires up when cranking?

[christja]

Mine was doing something like this a few years ago, turns out the lift pump had gone out, and my fuel was low. I think with it sloshing around some air got into the lines and the truck just stopped running. After cranking for a while the air got out and she fired back up.

[Brofer]

I have recently found that my injection pump is having issues. Could this be solved by replacing the PMD by SS. I was wondering if anyone has used ss diesel PMD units and are they holding up?Anyone? Do they help out enough or would one just replace the whole injection pump unit. There is a big cost difference and I want to make a good decision.

This is the low down of what has been occurring

The truck fired up fine yesterday morning and ten minutes later the truck stops running and all electrical units stay running (radio,fan,dash lights). I try and start it and it will not fire but cranks strong. I let it sit without trying for 15 min and it fired right up. I drove the truck around most of the day and it had not occurred again. I dropped it to my local diesel shop for further investigations.

[backcountryburban]

I have spent hours reading throught the appropriate posts on this subject and the more I read the more it appears that many members are experiencing small variations on how and when this situation occurs.
I am starting to think my truck is cursed, but there must be a cure for the disease.
Last week I was leaving a jobsite and withing 5 minutes of travel I was stranded on the side of the road. Right after I made a turn and then a right the truck kind of hick uped but continued running. I made it to a stop sign, made one last left turn and upon acceleration from the stop sign the truck shut off. Because it has done this numerous time before I was sure I could just pull over to the side of the road, take a rest for a bit, restart it and be on my way again. This time not so lucky! I noticed my voltmeter was reading dangerously low, almost into the red so I tried to start here one last time. She started and ran for less than a minute and shut off again. With no juice left, I called for a jump start. We spent the next hour trying to get and keep this truck running. Even with the other vehicle running and the truck running it would still shut off. The volts meter was still not registering a full charge yet either.I lost count of how many time we restarted the beast. Sometimes it would run for 5 second and shut off and other times it fooled me by running a few minutes. These were the times where I would be out of the truck and just about to remove the cables. Brutal! Finally with a $60.00 tow bill upon me I decided to try it one more time while I was waiting for my tow. It started and actually stayed running. My father suggested I try to drive it home to avoid the tow charge, I said her was crazy, I won't make it one block! But I agreed to give it a try. I ended up making it all the way home almost 30K with no problems! While on the highway, the voltmeter was reading over 14 volts which I believe is just right!

I have changed one of the batteries last year and the alternator as well.
The alternator was not the problem, it turned out to be one of the two damaged wires coming off the alternator connector. I cut out the damaged section and soldered it. When you wiggled this wire while broken it had the ability to make the volt meter read low or over 14 volts.

The most recent problem was to do with my blower motor quitting and no speeds or speeds without high. This ended up being a crucial ground circuit problem, which I believe I have now fixed. My electrical shop confirmed the problem was a bad connector under the passenger side of the dash which the blower circuit also happens to be on. On the wiring diagram it clearly showed that a number of other major circuits share this common ground. I was told this ground would have also effected the problems I had previously, which were related to the power door locks and the reverse light coming on while I was making left hand turns or stepping on the brakes! Oh ya those were fun times. But those problems have not come back for a year or more.

The most current gremlins have been the blower motor ground side of the circuit and the shutting off of the engine!

What would be the best step by step procedure to follow for a self diagnosis?
Check alternator output, what should it be?
Disconnect both batteries and test, what should they read no matter what?
Positive terminals, fully clean with baking soda and wire brush to remove any corrosion if I find any and seal with vasaline.
Check all the grounds, are therey only seven and where are they all located?
These are what I plan to do today but beyond this I am stumped. My local GM dealer is useless when it comes to these engines!

With a SS heat sink and replaced PMD, how could this be the problem?
I started thinking fuel problems and not electrical, ie pump, bad fuel, dirty filter etc, but how could the truck have made it all the way home if I had a fuel starvation problem????

I have been stranded a number of times and would greatly appreciate any expert help from anyone on this forum.

S0RRY FOR THE LONG POST!:[/B]confused: :confused: :confused:

[Chevylover]

1. Ever replace BOTH batts, because if one goes bad, it will tear the other also.

2. Even with the FSD Heatsink, the PMD could go bad. Too much heat at the intake. Heat will rise above -physically. Out of the engine bay, in the bumper holes, at the skid plate or between driverside batt and radiator attached to the battery tray.

3. Bad FuelSolenoid or wire.

But i think 1.or 2. could be more possible. Get a spare PMD, put it in the glove box and wait until the problem comes back. Than hook up the spare PMD an see what happens. If it fires up and runs without problems, the PMD was the prob. But first of all, you should have checked you alternator (load test and get both battes tested - disconnect each and test each one for itself).

Cu,
Sven



Cu,
Sven

[Sasquatch]

Makes you wana get package of hot dog, sack of marshmallows, six pack of cold adult beverages and MATCH!! Only guess PMD. My truck reads 13.8 volts running @ the battery and 12.7 off.

[backcountryburban]

Thank You very much Chevylover for the feedback. I made a plan and you helped me to move forward with checking everything systematically. I will post the results of the diagnosis process.

[backcountryburban]

Thank you for you feeback Sasquatch! I have noted your volt readings you provided to me.
Cheers!

[backcountryburban]

Where is the fuel Solenoid and what is the best way to test the wire?

[Chevylover]

Where is the fuel Solenoid and what is the best way to test the wire?

The fuel solenoid is the silver cylinder on the driverside bolt on the Injection pump. See attached picture ! Just run a wire from 12V to the pink wire. Than the solenoid should cklick, you can hear and feel it.

Cu,
Sven

[backcountryburban]

Thanks Sven!

[backcountryburban]

The truck seems to be running fine right now, by I am still checking everything I can. In particular the charging system!

I have two black wires going into the selenoid and there is no pink wire. I would assume one is pos and the other neg. How to tell which one?
I am also going to check supply pump pressure at the the Tee handle, 3-5 psi correct? The supply pump will either work or not correct?

Vacumn should also be 15" at the wastegate actuator and 20"+ at the pump correct.

[backcountryburban]

Attention Chevylover,
I have 14.65 Volts off the alternator when running, 14.61 off the drivers batt running and 14.60-14.61 off the pass batt when running.
Passenger batt @ 12.66 Volts leeds disconected.
Drivers batt @ 12.68 Volts leeds disconected.
The batteries were not load tested as I will have to take it to a shop for that.
All seems good!:)

[Chevylover]

Follow the two wires of the FSO solenoid to the connector. After the connector, there should be one pink wire. The ones direct from the FSO solenoid are the same color, but after the connector different !


Battery voltage data seems absolutly normal. About 12,6 if not hooked up to anything -only voltmeter and about 14,6 -14,7 at the alternator is also good.

If the load test is good also, you'll be fine with them.


Cu,
Sven

[backcountryburban]

Thanks Sven, I will run the test today.

[JD_countryboy]

Batts must be load tested to see if they are good. I had starting trouble, after much head scratching it was 1 bad batt. Voltmeter readings 12.6 + all the time. Finally took and load tested them, 1 bombed. it dropped under 4 volts. Load testing is the only good way to check battery condition. Unless you have a refractometer and want to pull a sample of each batterys acid and check specific gravity of each batterys acid. Load testing is cheaper and probly easyier for most of us. Most all stores will do it for free, but ya, gotta have them disconected to do it.

[Chevylover]

Batts must be load tested to see if they are good. I had starting trouble, after much head scratching it was 1 bad batt. Voltmeter readings 12.6 + all the time. Finally took and load tested them, 1 bombed. it dropped under 4 volts. Load testing is the only good way to check battery condition. Unless you have a refractometer and want to pull a sample of each batterys acid and check specific gravity of each batterys acid. Load testing is cheaper and probly easyier for most of us. Most all stores will do it for free, but ya, gotta have them disconected to do it.

That's what i said. See my posting above :

If the load test is good also, you'll be fine with them.


Cu,
Sven

[backcountryburban]

Regarding load test of the batteries, they were all shot and I have now replaced them a week ago. Considering they are rated at 675 CCA, One actually tested at 44 and the other was 53 Cold Cranking amps. Sorry, the voltage readings were 12.52 and 12.53 during the load test.
I guess you can have good voltage but the CCA capability is what determines if the batteries are shot??? Brutal!
With the new batterie in now I am still going to have the entire system checked again.
What voltage reading should I see on the instrument panel when you firt turn on the ignition to start the truck?

[backcountryburban]

Ok, I was stranded again, this time in a Home Depot parking lot with my two young kids and freezing snow and rain.
We went to leave and the truck just shut off. Wasted over an hour again, start, die, restart, die, restart with no start, let sit try again with restart, let run for 5 min- get ready & start to drive away and shuts off again, stuck in middle of intersection with dead truck, jumped out and pushed the beast out of the intersection by myself. Brutal and really a freakin dangerous situation. Finally called towtruck to take us home. While waiting for tow, truck stayed running for over 10 minutes with no shut off, I decided to chance it and try and drive home, it made it no problem.
When the truck shuts off the check engine light comes on with the battery light. During one of the many restart attempts, I also noticed I had no rpm, voltage, boost, tranny temp, or egt guages working either.
When I revved the engine on the restart the rpm guage kicked backwards, counter clockwise.
What the heck is really going on????????
Fuel or more electrical problems?
How could it be the PMD again???
It was new on the Cooler from Walt.
How long are these stupid PMD's meant to last??????
PLease help us anyone???

[Chevylover]

Regarding load test of the batteries, they were all shot and I have now replaced them a week ago. Considering they are rated at 675 CCA, One actually tested at 44 and the other was 53 Cold Cranking amps. Sorry, the voltage readings were 12.52 and 12.53 during the load test.
I guess you can have good voltage but the CCA capability is what determines if the batteries are shot??? Brutal!
With the new batterie in now I am still going to have the entire system checked again.
What voltage reading should I see on the instrument panel when you firt turn on the ignition to start the truck?

That is correct. Due to that the batts were both shot, i would made a circle around your electrical system (battery cable, alternator, fuel shutoff solenoid, ignition switch + harness, etc)

You wrote in a previous post : The alternator was not the problem, it turned out to be one of the two damaged wires coming off the alternator connector. Perhaps the charging controller INSIDE the alternator is going more and more bad after the wire problem. Did you get the alternator (load test) checked also ?

All grounds - i mean really all grounds checked ? Also the blower motor ground, which gave you trouble time ago, as you mentioned before ?

If all things above are okay and no problems, then ..... Auto meter tri- guage pod w/ EGT,Boost &Tranny temp.....Old school Clarion Pro Audio head unit........... Perhaps there or somewhere else is an electrical gremlin, that seems to be sucking 12V power or cutting it.


Cu,
Sven

[backcountryburban]

I love the beast too much too much to quit now, and will just have to continue the search for the problem one more step at a time. I can't bare the thought of getting rid of her at this point in time.
I sure wish there was an easy way to check or iliminate the PMD as the cause.
It sound like you fully agre with me that it is not a fuel problem, rather a electrical related problem.
Do you agree I should stay focussed on the electrical system for now???

Thanks Sven.

[backcountryburban]

Sven,
After the truck shut's off and I am able to crank it over and over without it firing, does this sound more like a fuel starvation problem which could be a result of a electrical problem with a fuel system related part? Or is this how a failing PMD behaves?
It sounds like a failing PMD behaves very similar to an electrical gremlin.
Sometimes it acts up and works fine the rest of the time.
I just can't afford to buy another PMD right now to keep as a spare in the glove box for the next crisis.
It sounds like a full electrical system diagnosis is in order asap! I will utilize your testing checklist with my shop who found the blower bad ground circuit!
Cheers!

[grancito]

Ok, I was stranded again, this time in a Home Depot parking lot with my two young kids and freezing snow and rain.
We went to leave and the truck just shut off. Wasted over an hour again, start, die, restart, die, restart with no start, let sit try again with restart, let run for 5 min- get ready & start to drive away and shuts off again, stuck in middle of intersection with dead truck, jumped out and pushed the beast out of the intersection by myself. Brutal and really a freakin dangerous situation. Finally called towtruck to take us home. While waiting for tow, truck stayed running for over 10 minutes with no shut off, I decided to chance it and try and drive home, it made it no problem.
When the truck shuts off the check engine light comes on with the battery light. During one of the many restart attempts, I also noticed I had no rpm, voltage, boost, tranny temp, or egt guages working either.
When I revved the engine on the restart the rpm guage kicked backwards, counter clockwise.
What the heck is really going on????????
Fuel or more electrical problems?
How could it be the PMD again???
It was new on the Cooler from Walt.
How long are these stupid PMD's meant to last??????
PLease help us anyone???
That is an electrical gremlin, bad ignition switch, bad contacts behind the instrument panel, or more likely a bad ground to the instrument panel, somewhere on the fire wall. Especially as you get negative rev reading.

[John R]

I have recently found that my injection pump is having issues. Could this be solved by replacing the PMD by SS. I was wondering if anyone has used ss diesel PMD units and are they holding up?Anyone? Do they help out enough or would one just replace the whole injection pump unit. There is a big cost difference and I want to make a good decision.

This is the low down of what has been occurring

The truck fired up fine yesterday morning and ten minutes later the truck stops running and all electrical units stay running (radio,fan,dash lights). I try and start it and it will not fire but cranks strong. I let it sit without trying for 15 min and it fired right up. I drove the truck around most of the day and it had not occurred again. I dropped it to my local diesel shop for further investigations.

I bought 1 from ss diesel and had a gm dealer install it.only to find them say it was no good! I contacted walt and he assured me it was good! I took his word on it and towed my truck home and got it running! (with help from walt) Walt assisted me in telling me what to check and so forth.I later found out that the problem was not my injection pump but rather my crank sensor. you can read about it on some of my posts.

[John R]

That is an electrical gremlin, bad ignition switch, bad contacts behind the instrument panel, or more likely a bad ground to the instrument panel, somewhere on the fire wall. Especially as you get negative rev reading.

Have you tried retightening the bolts on the pmd or fsd (same Crap) Lol? i have fsd with a cooler and ran into the same problem it left me stranded to. I fiddled with it to only to find out that the bolts mounting the Fsd had loosened off a bit! check them and retorque them. not sure now to what torque setting sorry I did that and its worked fine since.

[1962beachboy]

I have similar problem. 14 volts at alternator and about 12 running...about 10-11V ater glow plug relay goes to open. Have just started to clean and run down grounds.....We'll see? Interesting about the blower motor??

[kwilks27]

With the truck running try wiggling the wiring connector on the pmd and see if it shuts down mine does this and i just replaced the connector and she runs fine

[Oldsmoke]

Apparently they are getting the bugs out of the PMDs from that other manufacturer mentioned in this forum. They are a little thicker than the Stanadyne unit and a tight squeeze when mounted to the pump but about half the price.

[Chevylover]

Apparently they are getting the bugs out of the PMDs from that other manufacturer mentioned in this forum. They are a little thicker than the Stanadyne unit and a tight squeeze when mounted to the pump but about half the price.


Perhaps that is the reason, WHY they made it thicker ? LOL !
You should not mount it to the pump. How long you're a member here ? Nothin' learned ?

Sorry, just kidding -couldn't resist !


Cu,
Sven

[Oldsmoke]

My apologies Sven. Hope I didn't mislead any juniour members. As we all know NEVER MOUNT YOUR PMD TO THE PUMP

[John R]

My apologies Sven. Hope I didn't mislead any juniour members. As we all know NEVER MOUNT YOUR PMD TO THE PUMP

Thats right guys! It should be considered a crime to mount that blasted thing back on the injection pump! :rolleyes: Thats why we call it a fsd and not a pmd!

[macertheracer]

I had the verry same problems on My '95 turned out to be the pmd connector as well, I found it by wiggling the wiring harnes on the IP. and it started and stayed for a while, so i narrowed my efforts to individual connectors. I was able toget it running on one such ocasion, by wiggling the PMD harness it died. concentrated my efforts there, was able to repeat the problem several times. it is a very poor conector design and even worse individual wire pins. I purchased one of Walts extension cables, cut my connector off cut one of Walts connectors off and soldered/heatshrinked the wires, no problems since:) also went remote with PMD