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87 350 w/ tbi bogging down

Discussion in 'The Garage' started by blackguns, Aug 26, 2005.

  1. blackguns

    blackguns Newbie

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    Hello all. I hope someone here can help me out. I've got an 87 Blazer with tbi and when I really get on the gas, the engine bogs down, has no power, then slowly creeps back up. I've seen this problem a few other places but no solutions. So far here's what I've replaced: Fuel filter, fuel pump, plugs, wires, distributor, coil, coolant temp sensor and the gasket under the tbi. I advanced the timing and had two voodoo witchdoctors speak some unholy words with dead chickens. Sorry bout that last part but I think that's next. My next plan is to replace the fuel regulator in the tbi. Any help would be great. Thanks in advance.
     
  2. dirtwarrior17

    dirtwarrior17 Banned

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    sounds like the O2 sensor to me...

    Is it throwing any codes?
     
  3. spearchucker

    spearchucker 1/2 ton status

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    What gear ratio and size tires do you have?
    What size engine and how many miles?
     
  4. dirtwarrior17

    dirtwarrior17 Banned

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    says 350 in his title...


    If you stomp on the gas and it bogs when it should downshift it could be the tv cable also...


    My guess is the o2.
     
  5. spearchucker

    spearchucker 1/2 ton status

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    :doah::doah::doah:
    I must be getting tired.
     
  6. oatsk5

    oatsk5 1/2 ton status Premium Member GMOTM Winner

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    revisited so i just bought an 89 and love it but when i punch it the trany down shifts and the engine bogs un til i let off a little im new to tbi so any ideas help
     
  7. blackguns

    blackguns Newbie

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    Hey Oats, that is a lovely experience isn't it? Also, it wasn't the O2 sensor either. I just picked up 2 new (to me) tbi units for $40 so I figure I'll start screwing around with those soon. My truck still has the same problems but I'm building up one Hell of an xtra parts bin. If you happen to figure this one out, I would be eternally greatful if you'd let me in on the secret. I promise to do the same. Take it easy
     
  8. oatsk5

    oatsk5 1/2 ton status Premium Member GMOTM Winner

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    hey man you know it il pass it on
     
  9. oatsk5

    oatsk5 1/2 ton status Premium Member GMOTM Winner

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    what shape is your exhuast in good or bad im wondering i found in another post that backpressure may or may not be causeing trouble and the muffler on mine is fried just a thought
     
  10. k5freak44

    k5freak44 1/2 ton status

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    i have the same prob too. anone else have an idea???
     
  11. tx_sub

    tx_sub 1/2 ton status

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    my sub does the same. i think its just the nature of the beast (tbi). they aren't hotrods to begin with, and after 200k miles, power is lacking. i do have 3.42's and 31", but i live with it...for now.
     
  12. mouse

    mouse 1/2 ton status

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    An engine needing a tune would bog like you describe, but you'fe replaced most regular tune up items. Timing is controlled by the computer, so that should be good. A fuel pressure problem could cause it, but I wouldn't start with the regulator. If you can measure pressure at the TBI inlet would be the best. I would suspect a clogged sock in the tank, or filter (although I'm sure you've replaced that). Measuring fuel pressure under a load may show you a problem getting enough fuel to the TBI to maintain pressure. Checking with a gage has to be easier than dropping the tank to replace that sock.
     
  13. oatsk5

    oatsk5 1/2 ton status Premium Member GMOTM Winner

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    sweet thanx mouse
     
  14. kram

    kram Registered Member

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    if ya can get high rpm's i can't be plugged exhaust or lack of fuel???
    some thing to do with wot (wide open throttle).
    egr should cut off,est should change the timming to the extream.
    maybey the tps has a dead spot or map sensor bad/kinked vac line.
    my egr sticks open and gives rough off idle bog.
     
  15. oatsk5

    oatsk5 1/2 ton status Premium Member GMOTM Winner

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    thanx for the insite i got to thinkin bout what mouse said i use to own a heep xj and got rid of it but any wya it had the 4.0 it had the same symptoms sp? anyway it ended up being the fuel pump
     
  16. blackguns

    blackguns Newbie

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    Problem solved

    Well Goddamn! Finally, after too much time and hundreds of dollars of $40 parts it's solved. Dirtwarrior17 was right. It was the TV cable. Didn't really even have any slop in it but after really working the release in and out with a screwdriver and readjusting the cable a couple times it's working great! I also found a good sized hammer repeatedly smashed on the bracket holding both cables just plain old made me feel better. I hope this helps anyone having this problem. The only downside is now that it's got it's balls back, I have to worry about the chipped gears in the ass end. At least I'm never bored. Thanks all!
     
  17. oatsk5

    oatsk5 1/2 ton status Premium Member GMOTM Winner

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