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'91 GMC engine "cuts out"

Discussion in 'Chevy Trucks' started by bison1973, May 13, 2005.

  1. bison1973

    bison1973 Member
    Messages: 69

    My '91 GMC K1500 (350ci, auto) with 218,000 mi was running fine until recently. It has started to "cut out" or lose all power for a split second while driving. Then it will go back to normal. This can happen several times in a row or only once on an entire trip. It does'nt seem like a miss because as I said before it loses all power for a split second. It's almost like it just shuts down for a moment. Any help is greatly appreciated.

    Tim S.
  2. bison1973

    bison1973 Member
    Messages: 69

    Does anyone have any ideas????

  3. karl klein

    karl klein Senior Member
    Messages: 557

    i have a suburban 97 with the 7.4ltr that had a real bad mis once in a while and i found out it was a vacuam leak you can take a bottle of carb and choke cleaner and spray it around your vacuam lines to look for a leak when you find one the engine will rev up you can hear it real will. tyou could try that
  4. schnitz

    schnitz Member
    Messages: 98

    Have you got any idea what the fuel pressure is? Might be an intermittant fuel pump problem.

    In a while, Chet.
  5. PremierLand

    PremierLand PlowSite.com Addict
    from detroit
    Messages: 1,572

    i had a 94 f150 that did that. i replaced the fuel filter, almost replaced the pump and almost yanked the tranny, and then the mechanic found some corroded wires by the trans, he put in new wires and it ran great after that.
  6. Yaz

    Yaz PlowSite.com Addict
    from NH
    Messages: 1,061

    I could be anything.

    This is what I would do...

    Was it wet out when it did this?
    No.. may be fuel like stated above...
    Yes..most likely electrical
    Check wires for arcing in dark garage, and inspect for lose wires around coil...
    Was it tuned up lately?
    No... replace cap and rotor, plugs
    Yes.. check coil under a load. put truck in drive and hold with break, apply gas and see if it pops and breaks up under load.
    No... not the coil
    Yes.. could be coil or shorted plug.
    Check plugs
    Plugs Good..swap coil to test from buddies truck...lol
    Plugs Bad.. replace and retest coil under load

    Good Luck
  7. Gmgbo

    Gmgbo Senior Member
    Messages: 159

    i just had that same problem, it was the fuel pump
  8. MickiRig1

    MickiRig1 PlowSite Veteran
    Messages: 3,617

    Electric fuel pumps are real sensitive to voltage supply. I would look for a bad connection (pump,relay,wires to pump,ground) or bad fuel pump relay. I would bet Chevy is like my Fords, the computer relay energizes first then it energizes the fuel pump relay. If you have two tanks and 3 pumps the tank switcher could be the problem too, like bumps it sputters etc.
  9. Gmgbo

    Gmgbo Senior Member
    Messages: 159

    did jsut the engine cut out or did the truck lose power completely(like the radio and lights go out)
  10. procut1

    procut1 Senior Member
    Messages: 380

    We have an 88 chevy 2500 pickup 350 gas engine

    This truck would be running great then going down the road it would do the same thing-----power to the truck would be cut for a second and come right back. It seemed just as if you turned the key off and turned it right back on.

    It would especially do it if you had the wheel turned to the right,

    We spent a day trying to figure it out. Then we had it to 3 different repair shops.

    After having the entire ignition system and most of the fuel system replaced...the problem was still there.

    Took it to a friends shop and he ended up finding a bad ground between the body and the chassis..... Try that before you do anything else.

    Get a battery cable and attach it to the body somewhere and then attach it to the frame......
  11. nextdoorlabor

    nextdoorlabor Junior Member
    Messages: 16

    definetly try the basic tune up, plus fuel filter, the new ground idea sounds solid too... dont count out the ecu or pcm computers either, i had an ecu go bad and it would do the same thing to me, i would be going down the road and it was like it skipped a beat then it would take off again. also check the battery connections at the terminals, they have been known to come loose. if its the original fuel pump it could also be shot after 200k+ miles. good luck with that
  12. Gmgbo

    Gmgbo Senior Member
    Messages: 159

    my 89 is cutting out, but all the electronics are staying on. it has new plugs wires, air filter, fuel pump and filter, and recently rebuilt trans
  13. MickiRig1

    MickiRig1 PlowSite Veteran
    Messages: 3,617

    Sure you have fuel pressure when it cuts out?
    Both my 86 Ranger and 89 F-250 would lose fuel pressure and it would die.
    Sometimes it would start right up other times it took awhile.
    I found out what was making them die by putting a temporary pressure Gage on the fuel rail and carried a timing light with the trigger taped on. When they died I popped the hood and put the timing light on the coil wire aimed toward the drivers seat and tried to start the engine. Most EFI systems have the same stuff from Brand To Brand. So my Fords are not much different from your Chevy's. Check all your connections on the power circuit for the pump or pumps,relays do fail I have replaced 3 so far. My 89 had the tank switcher / reservoir fail. My 86 was a bad relay that would heat up and shut down.
  14. Gmgbo

    Gmgbo Senior Member
    Messages: 159

    Thanks for the advice it ended up being the sparkplugs lol