Truck wont START???

Discussion in 'Trucks and Trailers' started by scraper69, Aug 22, 2005.

  1. scraper69

    scraper69 LawnSite Senior Member
    from mi
    Messages: 477

    ok.. wed. we used this truck (GMC 3500 P/U for the first time in a couple months. Was pretty low on gas, but sat at jobsite. Then wen to start, and no go... just cranking. Ok well obviously out of gas... so we get gas in it and fire ... nothing now the starter is going.. so after jumping the selonoid and getting it to crank over , but still no start. NOW What.... well i decided the fuel filter must be clogged.. so we change and wiht a shot of starting fluid the truck started and ran back to the shop./

    Today i try starting and no go... just cranks and cranks ...

    What could this be????
  2. riches139

    riches139 LawnSite Senior Member
    Messages: 369

    When was the last time you changed the plugs?
  3. scraper69

    scraper69 LawnSite Senior Member
    from mi
    Messages: 477

    Its been a couple years/?? you think it could be plugs?? what about fuel pump.. thats what i thought. anyway it s a 1992 Gmc 350 5.7 EFI

    UNISCAPER LawnSite Bronze Member
    Messages: 1,426

    Fuel pump is in the tank on that one. With weak electrics comming from the battery, and possibility of a charging problem, bring all your electric systems up to norm before you look else where. After all those systems are on track, you can check fuel pump pressure. As a rule, tank fuel pumps either work, or they don't. There have been a few times where we banged a tank enough to get one to turn only to have it fail on the way into the shop. And if it is a fuel pump, be careful. when you remove all that snakedy mess the illustrious EPA requires to be installed on the tank, the plate will most likely have corroded ends under the hoses. If you can save it great. Most of the time, you end up needing to replace the plate. Sit down when you get the price...Near $300.00....

    Most likely, you have a dirty oil, plugs and tune up problem...We could always tell it was spring back when we had a '79 ford 250 with a 460. It would not start, then you replace wires, cap rotor and plugs, and it would fire right off....
  5. xcopterdoc

    xcopterdoc LawnSite Senior Member
    Messages: 752

    Besides what Bill mentioned, another known failure in the fuel system is the wiring pigtail from the harness to the pump, under the plate. As the pump fails and draws more current, it melts the connectors on the harness.(inside the tank) I always order one when doing a pump,along with a new pick up screen. Also, near the battery sticking out of the harness, you will find an orange wire, with a female spade connection. Apply 12 from the battery to this wire and fuel pump should run, if it doesnt, unplug the connector at the tank, check for battery voltage on the gray wire... if you have power, its a bad pump. If all that checks out, and yur sure its a fuel issue, you may have picked up some trash and it ended up in the fuel pressure regulator in the throttle body, before it gets to the injector. Good hunting and post back with the fix.
  6. scraper69

    scraper69 LawnSite Senior Member
    from mi
    Messages: 477

    Now what... today. i just tried for the heck of it..and fired right up.. WTF???
    well i m gonna change plugs just to see what they lookk like and go from there. This is goofy???
  7. The Good Earth

    The Good Earth LawnSite Member
    Messages: 171

    There is an Ignition Control Module that sits under the rear of the distributor cap. It is about 3-4 inches long and a 1/2" thick. It has 2 different electrical connections going to it. It sounds like that is your problem. They take about 1/2 hour to fix, only held in place with 2 10mm screws. The part is this: Module

    It sounds like that is what it is. Mine has gone twice. Once in my 3500, once in my 1500. make sure you grease the bottom of that thing real good when you put it in. Heat just kills it.
  8. StealthDT

    StealthDT LawnSite Member
    Messages: 97

    When the Ignition Control Module goes, it doesn't come back to life. I vote the fuel pump and/or the wiring to the pump. Happened to me on my '97 chevy. Was lucky to have a dump body where I didn't need to remove the bed or fuel tank to fix it.
  9. The Good Earth

    The Good Earth LawnSite Member
    Messages: 171

    Well, you have certainly had more luck than I have with the module. Both of my trucks both went through the no starting thing intermittently for about 3 days until I got them on a computer and figured that they were on the blink.

    Also, it is easy to check the fuel pump. Have somebody turn the key while you are under the truck. Just turn it to the "on" position but don't start the truck. You should hear the fuel pump motor kick. If it doesn't kick turn the truck off and hit the fuel tank a couple of times with a rubber mallet. I know it sounds hillbilly but it sometimes moves the solenoid on the fuel pump. Try to start the fuel pump motor again. If the motor still doesn't kick then your fuel pump is shot.
  10. The Dude

    The Dude LawnSite Member
    Messages: 221

    I know that sometimes when a electric fuel pump is run dry it will kill the pump. I would definately lean towards the fuel pump being gone.

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