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tbi problem

Discussion in 'The Garage' started by mechanical1973, Feb 9, 2005.

  1. mechanical1973

    mechanical1973 Newbie

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    just wondering how many others have run into this problem.

    I have an 87 k5 blazer with the 5.7 tbi motor and automatic trans.
    It constantly shuts off (mostly at low rpms like at a red light or stop)
    No codes show up, but the vacuum gauge does indicate low vacuum at idle - it actually indicates "sticking valves" I checked for leaks by spraying carb cleaner but could not find any.

    What I did notice is the return fuel line has a very bad kink in it just as it turns down the firewall. Not sure if this would cause this problem - from what I know, this would increase the fuel pressure in the system right ?

    Anyway, if you guys have any suggestions or have come by this problem let me know. I'm close to dumping this tbi set-up and going carbureted.

    thanks
    nelson
     
  2. blazerguy 90

    blazerguy 90 1/2 ton status

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    Idle Problem

    The first thing to check is the gasket between the intake and throttle body, next thing to check is the IAC, if its real dirty it won`t operate properly, you might also consider removing the TBI unit and giving it a good cleaning, there are several vacuum passages cast into the bottom of the TBI that can get plugged, also check your EGR valve, if its plugged or bad it can also cause the problems your having.
     
  3. clarkjw24

    clarkjw24 1/2 ton status GMOTM Winner

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    Yeah what he said. lol

    I'll take that tbi setup off of your hands when you junk it. :xmas:
     
  4. dyeager535

    dyeager535 1 ton status Premium Member

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    So lets see...the fuel line return has a bad kink in it, and the engine has low vacuum. Thus, TBI sucks and a carb will solve these problems? Fail to see the logic here.

    *Logic* says that you have two known problems, and fixing them can't make your problem worse.
     

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