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  1. #1

    Default Buying 1990 GMC suburban..need help!

    I'm finally getting close to buying the Suburban I wanted for some time now. The old "tank style box" 1990.

    The current owner says the main problem with it right now is , when its cold(sitting all night ) it starts and runs fine . when its hot, it starts and runs fine.

    However, if its anywhere inbetween, as cooling off from hot, or not completely warmed up, it wont start and a fuel smell is coming from the motor as if its flooding etc.

    What could possibly be causing this to happen? What can i test to see what it my be?

    I'm looking forward to getting this beast!!!!!

    Thanks for any help you can give.


  2. #2


    Bad injector(s) maybe? Vacuum leak somewhere?


    '94 Chevy Suburban K1500
    3" exhaust w/ aero turbine non-baffled muffler
    CFM Technologies TB spacer
    CB w/ 44" whip antenna

  3. #3

    Default 80% of time runs great

    The owner says it runs fine 80% of the time. Its just that brief window that it wont start and smells of fuel, like it flooding. Other then that, runs great.

    Is there any sensors that would tell the fuel system to pump fuel in or???

  4. #4


    run a scanner or jump the term and see if there are any codes then look at those issues.....mike
    Michael Collins
    1993 4X4 Suburban
    many other toys as well

  5. #5

    Default codes???

    I know on my Dodge diesel, I can get the codes by turning the ignition 3x off and on and they are on the odometer...How do I get the codes off of the GMC???

    Thanks. Ed

  6. #6


    The ALDL (looks like a multi pinned female plug) sticking out the bottom of the dash on the driver's side. Get a paper clip and jump the A terminal to B terminal (top row all the way to the right and top row right next to it) and turn the ignition on. The SES light will start blinking at you, read the codes and look them up.

  7. #7
    Jr. Apprentice
    Join Date
    Jul 2008
    South Florida


    a bad t.p.s sensor can cause that to happen. they are spring actuated and if the unit is bad heat can effect it. my father in law had the same truck with the same problem and thats what it was but as suggested read the codes first. the ses light will flash out the codes to you if you jump the terminals desceribed above. althought the code does not always pinpoint the cause.

  8. #8

    Default Found the problem

    The seller was baffled by the problem and it happened to him when it was cold the day before I came over...

    It would not start cold and he checked the spark and found none...He changed the ignition back to stock and the problem went away.

    Apparently the aftermarket "MSD" ignition(coil) system was intermittently not putting out spark.

    I have not had any problems at all. She runs like a top even with 230k on the clock.

    Thanks everyone for your help. Now I just have to find a good source of parts for it, dress up stuff, dash mats etc.

  9. #9


    I buy items from L.M.C. truck parts. Their on the web. This company carries a wide variety of what you're looking for.

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