94 Chevy 6.5 Diesel Starting Problem

Discussion in 'GM 6.5 Diesel Engines' started by LuvMyChevyTruck, Oct 20, 2010.

  1. LuvMyChevyTruck

    LuvMyChevyTruck New Member

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    I have a 94 Chevy with a 6.5 turbo diesel w/AT. We had some problems with it dying going down the road like you shut it off. We replaced the fuel shut off solenoid and put a remote PMD on it just inside the front bumper. I has done great for several months.

    Now I have developed a new problem I am hoping someone can help with.I took my son to the emergency room yesterday and when I got ready to leave it did not want to start. It would crank over real good but not start. I tried 3 times with the same result. I eventually thought of just shifting the gear shift all the way to low and back up to park. I sat there for a couple of minutes and hit the key. It started right up.

    I came home and around an hour and 1/2 later I had to go back out for something. The truck started right up and I backed out of the drive. When I put it in Drive from Reverse it died and it did the same thing as at the hospital, cranked good but no start. I moved the shift down and back up and it started. I have no idea whether moving the gera shift had anything to do with it starting or if it was just a coincidence.

    Any help would be greatly appreciated!
     
  2. WarWagon

    WarWagon Well it hits on 7 of 8...

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    1st post, Welcome!

    Check your lift pump. Sounds like it runs out of fuel and gives you the typical no lift pump hard starting. It will stall randomly without a working lift pump I have noticed.
    Look at the gear shift linkage for possible hitting wires. The gear shift is in the same area as the lift pump harness in places.
    Check grounds and positive battery cables.
    Check the PMD harness, what brand do you have?

    Possible ignition switch that the gear shifter bounces to life. :???:

    Lift pump diag below. Get a pressure test gauge if you don't own one as you will frequently need it. You could also look at a better pump like a Walbro or carter.

    http://www.thetruckstop.us/forum/sh...t-Pumps-amp-OPS-operation-and-troubleshooting
     
  3. LuvMyChevyTruck

    LuvMyChevyTruck New Member

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    Thank you WarWagon.
    The lift pump is working.
    He has cleaned the battery cables real good (since the last no start). It can't hurt but I don't know how that would be the cause when it turns over so good.
    As for the pink wire on the IP, sorry to sound dumb but what's the IP?
     
  4. WarWagon

    WarWagon Well it hits on 7 of 8...

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    Sorry my bad, Pink wire is DB2 like I have on the 1993. You have the DS4 electronic IP... Injection Pump.
     
  5. WarWagon

    WarWagon Well it hits on 7 of 8...

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    You will need to check the grounds as well. Esp for the PMD. Grounds look good till you take them apart.
     
  6. LuvMyChevyTruck

    LuvMyChevyTruck New Member

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    Thanks WarWagon! We are gonna check these things.
     
  7. ak diesel driver

    ak diesel driver Active Member

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    you need to do the OPS mod too. Oil Pressure Sender. It controls the lift pump while the engine is running and is a common failure. Oil pressure will still read fine just no juice to the lift pump.
     
  8. LuvMyChevyTruck

    LuvMyChevyTruck New Member

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    Thanks AK. yes I am familiar with this problem, I had to replace it before.
     
  9. buddy

    buddy New Member

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    Need some more info. You said it would stop like you shut if off. How literal was this? When you turn the key everything in the truck goes off, radio and anything on accessory. When this happens do you get an SES light with the ignition on or a glow plug cycle at all? If not then its a power to the PCM problem, likely from the ignition swith contacts being burnt.

    If its not like that then there are some other things to check.
     
  10. 540s10

    540s10 New Member

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    1st thing to check for is air in the filter manager, have you ran it low on fuel recently? air can accumulate in there if you are going up and down hills near empty, and that would cause symptoms you are describing.
     
  11. LuvMyChevyTruck

    LuvMyChevyTruck New Member

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    Thanks for the reply Buddy. Yes the dash lights come on but the truck just dies. It happens so fast with no miss or anything it's like you shut it off. it just does 1 fairly hard chug. Usually it would start right back up but sometimes it would crank and crank but not start until it sat there for a little bit.This has not happened while driving down the road since we replaced the PMD though.
     
  12. LuvMyChevyTruck

    LuvMyChevyTruck New Member

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    Thanks 540S10. No I have not driven it low on fuel like you mean but I did let it get to 1/4 tank which I had not done in some time. Not up and down hills and such though just across town. We changed the air and fuel filters today.
     
  13. Mightygiving

    Mightygiving New Member

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    check for cracks or blisters in the rubber fuel lines near the IP or rusted through or pinholes in the metal fuel lines. lower pressure lines aft of the LP will not show major signs of fuel drips so the frame rail at the lines has to be observed closely and be sure you look all the way back to the sending unit atop the tank as there are rubber connections and rust areas there as well...

    x2 for air in the fuel lines

    BTW, does it throw any codes (SES light go on) when this symptom occurs? If So, what codes?
     
  14. great white

    great white Active Member

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    With starting and running problems that seem related to shifter movement, have a look at the neutral safety switch.

    Unfortunately, the only real way to check these is replacement.

    Good news is they're not that expensive. Rock auto lists one for anywhere from 7-15 bucks so a local jobber should be close to that.

    Normally it won't even crank when these go south, but I've seen stranger things.....
     
  15. buddy

    buddy New Member

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    As long as you get a Glow plug light and SES light with Ignition then I would not suspect the ignition switch.

    Did you do any testing of the lift pump, or just heard it running? We have to be skeptical until some actual results are given, other than its working, because the LP is a very important part of the fuel system. If the LP was tested to show flow with the engine running, then I would be looking for air issues and check the fuel cap, or try it without the fuel cap on. If you do not have a venting fuel cap you can build too much vacuum that prevents fuel from getting to IP. If there are rusty rotted steel fuel lines on top of the fuel tank they will cause air intrusion from tiny pin holes, due to to vacuum from the LP. Sometimes taking the fuel cap off can relieve enough strain on the LP that it doesnt pull as much vacuum in the lines from the fuel tank so the issues become less frequent.

    Had you recently put on a new fuel filter and maybe didnt make sure the filter was clocked correctly, because it has keys and only goes down one way and commonly doesnt get set down right, but the plastic nut still goes on tight.
     
  16. NVW

    NVW Active Member

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    Another thing that will cause pmd like stalling is poor fuse spade contact. Shine up the ecm and fsos fuse spades withe emery cloth. They are in the under hood fuse box on 95 up, I'm not sure about the 94.
     
  17. qmedmike

    qmedmike New Member

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    Hello I just read about your problem with shifter ,went out and did exactly what you did ,and guess what started right up so I will be looking at lift pump.new member thanks mike t
     

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