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TBI problems: fuel pump, injectors...?

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by Blazinaire, Jun 4, 2002.

  1. Blazinaire

    Blazinaire 1/2 ton status

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    I have an '87 blazer with a TBI 350. For the past week it has been acting like my motor has a holley carb on it! Every bump that I hit or steeper hill that I climb, the motor will stutter like it is running out of gas. The thing is, I have a full tank of gas. I changed the fuel filter to no avail. Is this a sign of the in-tank fuel pump going out? Maybe something wrong with the injectors? Please help, this is my daily driver and I know little about fuel injection.
     
  2. HarryH3

    HarryH3 1 ton status Author

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    Sounds like you're losing electrical power somewhere. It could be a bad fuel pump, a bad ground to the fuel pump, a bad fuel pump relay, or even a loose connection to the computer itself. Also, the ignition module sends a trigger signal to the computer, which tells the computer how often to fire the injectors, based on engine rpm. If that wire is intermittent, it can cause the problem that you're seeing. Finding intermittent electrical gremlins can drive you nuts. /forums/images/icons/shocked.gif
     
  3. Thunder

    Thunder 3/4 ton status

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    Have you checked for trouble codes ?
     
  4. Blazinaire

    Blazinaire 1/2 ton status

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    I haven't checked for trouble codes (don't really know how) and the fuel pump ground wire is good. Is there any way to check the fuel pump without pulling the tank (will this show up with the trouble codes?)
     
  5. YtseJam

    YtseJam 1/2 ton status

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    Yes, Use a fuel pressure guage to check proper fuel pressure... Around 13 PSI is normal. Elaborate some more on the condition.
     
  6. Blazinaire

    Blazinaire 1/2 ton status

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    When driving down the highway the truck will not stutter at all. When I drive down washboard roads the thing seems like it is only firing half the time. This condition seems to be even worse when the road is uphill. If I stomp the gas from a dead stop (on smooth pavement) it does not hesitate. Kinda sounds like a loose wire to something huh?
     
  7. YtseJam

    YtseJam 1/2 ton status

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    Check your distrubutor cap, sounds like that is the area to look
     
  8. 1BAD88

    1BAD88 Registered Member

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    I had a simular problem a while back .It turned out to be that the plastic baffle in the gas tank broke loose and was bouncing around in the tank and it broke the top welds on my sending unit and somehow it would make the truck shut down every time I hit a bump or steered hard to the right.I looked at everything to find it and it drove me fuc*ing crazy till I dropped the tank and figured it out.So what I did was cut the baffle out of the tank and I bought a new sending unit and fuel pump and I put it back together and the truck never had that problem again.hope this helps good luck..........
     

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