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Thread: In need of help! Will pay or buy a gift for the one to solve this puzzle.

  1. #1
    Join Date
    Jul 2020
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    Default In need of help! Will pay or buy a gift for the one to solve this puzzle.

    Hello everyone! Please excuse my long post, but I figured I would give as much data as I can. I am at a loss of what my issue is, or where it came from. I feel like I am getting closer, but this vehicle is my first real venture into diesel engines. So excuse my ignorance, if any comes up.

    Here is what happened:

    2 months ago I found a very nice truck for sale. It is a 1998 gmc 3500hd with a 6.5 deisel. It has a 12x8 tilting flatdeck, its a dulley, and a standard transmission. it has 300k km on it (180 miles), and the price was far too good to pass up. The only issue, it doesn't start.

    So I go and check it out, the guy said that one of his employees had run it dry, and he hasn't been able to start it since. He said maybie the injectors are burnt. but its priced to sell and he wants it gone. So I bought it, and figured with the price I got it for, worst case scenario I would just pop a new motor in it.

    I towed it away, and got a mechanic friend to come and help me get it started. At the time I had no idea what I was even looking at, and it was the first diesel i had ever messed around with. My friend cracked some injectors, and after about 45 minuted of messing around, he got it to fire up. Not only that, it sounded and drove excellent. I then used the truck for about a week, put maybie 300kms on it on the highway, and drove it around town for a couple quick errands. Great truck.

    after a couple days i went to take it out one night for a drive. That is when everything "began". I will go over the next events that took place over about 8 weeks in as much of a point form as I can.

    -while driving up the highway, it shut off as though the key was turned off. We pulled off the side of the road, fired it back up and drove off. It drove for about 3kms, died again, but now wouldn't start.

    -the following day I decided to go with lift pump because it was cheaper then a pmd. Upon doing this we realised the deisel smelled like gas. So we emptied boath tanks and the fuel lines as best we could(id say it was about 10 to 15 percent gas), replaced with new fuel, no change. when i took the pmd out to go get a new one i realised there was no resistor. So i bought a resistor, popped it into the pmd, and boom she fired up. I drove her back home (as she was on the side of the highway through all this), she ran great, and had no issues.

    - the truck then worked perfectly fine for a couple days, then all the sudden wouldnt start. It was mid afternoon, not cold, and had not been run for about 24hrs. I did an oil change (the old oil seemed high), replaced the fuel filter, and glow plugs. All to no avail. I then switched out to the new pmd, still nothing. Then traced all grounds, cleaned them good with a dremel, still wouldnt start. i then took a screwdriver, jumped the glow plug sylenoyd, and it fired up! But only ran for 5 minutes before dying and going back to no start.

    - I then towed it to an injection shop who spent 20 mins diagnosing it and said that the fuel injection pump was shot and quoted me 3k. I called the local wrecker, and my mechanic friend, found a cheap used pump and we decided to do it ourselves.

    - so my mechanic and I spent 3 days going over it and swaping pumps. when all was said and done, we bled it and the truck fired right up and ran excellent. we drove it on the highway for an hr, and all was well.

    3 or 4 days later I fired it up and to move it, and after a couple of minutes it died while in idle.

    we then went into diagnostics mode. We blew out all the injection lines back into the tanks, opened the tanks up, replaced the fuel socks, gave it 2 brand new lift pumps(one on each tank). made sure there was no leaks anywhere, and verified the tank to be clean. I also spent alot of time tracing wires, rechecking my grounds, checking sensors, and after some time we concluded that this 2nd pump we got from the wreckers must be shot too as we could get fuel up to the t, but not to a cracked injector.

    So we bought a standyne factory remanned pump and switched it out. We took our time to make sure everything was done precisely. My mechanic friend is an educated mechanic, i don't believe there was ever any catastrophic mistakes through any of this.

    So this is where things get really strange.

    After putting in the new pump, we bled the system, verified that we where finally getting fuel to the injectors. tightened everything up and started it. It idled like absolute ****, with loads and loads of white smoke pouring out. We took off the intake manifold, verified all injection lines by firing order, tried to rotate the pump a bit to get a different static time, but couldn't get it to run properlly.

    We then figured maybe the injectors are ****, so gave it an entire set of brand new injectors. no change, still pouring white smoke and idles super rough. we took off the timing cover and verified everything was in line, no teeth had been skipped.

    So i towed it to gm, that way it could be connected to a tech 2 and the electronic timing could be set properly. They immediately decided to forgo that and do a compression test instead. They came back with the results that I had 2 dead cylinders (2 and 4), 3 under spec, and 3 at spec.

    so at this point, we are quite confused. The truck ran excellent when it ran, and the only issue we found was that we couldn't get fuel past the injection pump. How could changing the injection pump cause the engine to blow? This trucks only noticeable issues where in the fuel delivery system. What the hell happened?

    anyways, we figured maybe the head gasket was blown. So we decided to do the head gasgets. and if there was an issue with the valves or the clips that hold them then we would find that working down. everything looked fine, and the head gasget did look a bit like it could have been blown. we poured liquid in all the cylinders to ensure they where holding liquid, wich they where. The heads themselves looked okay aswell, there was small cracks in between the precups, but apparently that is normal. Nothing really stood out to be broken or the cause of the issue.

    after doing the head gaskets, no change. at this point we are in one town over, where my mechanic lives, and i decided to take it to this GM. I told them the entire story, and asked that they look specifically at the timing. The spend a couple days on it, and couldn't figure out what the problem is. They verified that the timing is correct, both mechanically by looking at the gears, and electronically by using the tech 2. they said the problem has to be compression, and i must have a cylinder or two without compression. they advise to just ditch the truck (as everyone has pretty well through it all). The mechanic at gm did say i should try to remove the cat converter if it has one and see if that makes a difference. But they verified the timing is good, and the pump is in properly and the fuel system is fine.

    And now that is where I'm at.
    the smoke is white, not blue white, white. it smells like deisel. it is not sweet like coolant. The coolant, engine oil, and fuel do not seem to be mixing anywhere. I found nothing to suggest coolant in the oil, or diesel in the coolant. also, through all of this i had no codes present that weren't there from my diagnostics.

    what i am thinking my next steps are is to replace the head on the side that has the issue(passenger). my biggest concern is that the problem lies in the lower half and not the upper half. I would hate to replace the heads just to find out the block is cracked.

    my questions are this

    does anyone have any idea what diagnostics i can do myself to narrow down the issue?

    are there any theries as to where this problem came from and why the truck ran perfectly fine before all the sudden the engine was blown?

    are there any less drastic things I should do before taking the engine apart again? I did put clear return lines btw, and verified that i have no bubbles on the return side of the pump.

    is there like some kind of fluid i can add to the coolant to block partial leaks and maybe bandaid this so i can deal with it in the winter? Or how can i go about figuring out exactly where the loss of compression is? or exactly what part needs to be replaced?

    note that the tools i have are limited to a home type garage. I can not hoist the engine out. I do have all the wrenches and sockets i need, tourqe wrench. air compressor, basic obd2 reader. I wanted to buy a compression gauge, but for some reason they where like 800 dollars. So when recommending something to test, please consider that i have no real specialized tools.

    Please, someone help me through this. I really love this truck, it was my first standard, i bought it to use for my buissness, and it is sending me head first into drowning.

    if i can get it working i could at least carry on with my business and likely recouperate from this loss of 2 months ive sunk into it. The smart bet may be to get rid of it, cut my losses and get something else. but at this point I'm kindof past the point of no return, not just financially, but in spirit. I have to fix it now, call it ego.

    Please help! If someone can hit the nail on the head and figure out what the problem is, ill buy and send them a gift of some kind.


    TL;DR
    -1998 gmc 3500hd with 6.5 deisel
    -no start, no fuel to injectors.
    -new pmd
    -then used pump
    -runs good for a couple days then same issue
    -new factory remanned pump installed
    -now truck starts, but idles really bad, lots of white smoke and appears to have no compression in 2 cylinders.
    -pump timing has been verified as correct
    -head gasget has been done
    -as well as brand new injectors, lift pumps, and glow plugs.
    1998 GMC 3500HD, 6.5 Turbo Deisel

  2. #2
    Join Date
    Apr 2001
    Location
    CA
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    13,573

    Default

    Welcome aboard!

    No mention of the PCM or the ign. switch. If all the wires and connections are good, that's all that's left that might cause the grief. Either can be intermittent.

    All the mechanical issues that came up can cause problems, but none will cause your good-run/bad-run/no-run conditions. If it had a blown head gasket or "dead" cylinders in any way, you'd be going down a completely different road. Zero compression on 8 cylinders may prevent a start, but will not prevent sending in the fuel to try. If you have fuel to the pump I think your problem is a ways upstream. Think electrical/electronic.
    1985 Blazer 6.2
    2001 GMC 2500HD D/A
    dmaxmaverick@thedieselpage.com

  3. #3
    Join Date
    Jul 2020
    Location
    creston, BC
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    Default

    Quote Originally Posted by DmaxMaverick View Post
    Welcome aboard!

    No mention of the PCM or the ign. switch. If all the wires and connections are good, that's all that's left that might cause the grief. Either can be intermittent.

    All the mechanical issues that came up can cause problems, but none will cause your good-run/bad-run/no-run conditions. If it had a blown head gasket or "dead" cylinders in any way, you'd be going down a completely different road. Zero compression on 8 cylinders may prevent a start, but will not prevent sending in the fuel to try. If you have fuel to the pump I think your problem is a ways upstream. Think electrical/electronic.

    okay ill look into the pcm. I did look at the ignition switch when looking at the wires, and it seemed to be fine. Would a tech 2 scanner at gm not pickup some kind of fault in an PCM? And that still makes me wonder about the compression test that the first shop did, and why it came back with the results it did.
    1998 GMC 3500HD, 6.5 Turbo Deisel

  4. #4
    Join Date
    Dec 2003
    Location
    Yukon Canada
    Posts
    1,612

    Default

    I have a similar truck,it has a wrecker deck
    I kept having issues with it,even though it wasn't a daily driver it continuously had electrical gremlins.
    Went through 3 PMD's 2 were remote mounted tried both aftermarket and Stanadyne.Changed the Optical sensor,ignition switch.
    Everything i changed did get it going at the time.
    One day i went to start it to back it out of the shop and it cranked but wouldn't start.
    I did the usual diagnostics with no luck,spent a few hours trying to get it to run again.
    The next day i started the conversion to a mechanical pump.That solved all the problems.It was a reliable truck after that.I planed on the switch as soon as i bought the truck,it is a 5 speed standard so it was a simple conversion
    So after reading what you have gone through that would be my suggestion.You can sell you new electronic pump and get a new manual pump for the same money if you shop around a bit.
    90 Chev 3500 c/c 4x4,6.2na,400 auto,4:10 gears.DSG Timing gears,main girdle, isspro tach, pyro,boost,oil and trany temp.Dual Tstats, High volume peninsular pump,on shelf, Custom turbo and intercooler 85%complete. Change of plans for the dually, it's going to get a Cummins. Both trucks are Blue 90 4x4 crews

  5. #5
    Join Date
    Mar 2017
    Location
    Ohio
    Posts
    66

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    I had a truck that was similar. Figured it out and bought another truck that was similar. Both had remote pmd’s on them with the long cable with all black wires (i dont know if they are ALL like that though).
    Anyways, check the pins on the connector at the injection pump/pmd connector harness and the ones at the pmd connector/pmd. I have found 2-3 pushed out everytime. And BURNT. But you dont really see it unless you are looking for it.

    Seems like everytime you touch anything that has to do with that cable, you get a different result. At this point i solder and splice direct to the IP wiring. Never had a problem since.

    Also, i have seen compression gauges with a bad schrader valve read 0 when testing. I got fooled by that once, lol.

  6. #6
    Join Date
    Mar 2017
    Location
    Ohio
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    66

    Default

    Well? What did you find?

  7. #7
    Join Date
    Aug 2020
    Location
    Canada
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    Any codes pop up after installing the reman pump?Probably a tired injection pump harness from the pmd back to the firewall location.With all the hot and cold cycles the engine produces with the underhood heat,the harness has probably seen better days.

    When I say harness I just don’t mean from the pmd back to the armature location on the injection pump but the full injection pump harness that incorporates the optical sensor connector,stepper motor,intake air temp sensor,etc.

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