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smog controll on a 87 jimmy with 350

Discussion in 'The Garage' started by cavscout19delta, Jan 26, 2004.

  1. cavscout19delta

    cavscout19delta Registered Member

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    I just rebuilt my 350 in my 87 jimmy and took all the smog controll off and put a set of header on. Now i have extra wires hanging about, what did this do to my computer, and can i cut the wires? What about the ox sensor that when into the ex manafold ? /forums/images/graemlins/1zhelp.gif /forums/images/graemlins/k5.gif /forums/images/graemlins/peace.gif /forums/images/graemlins/ears.gif
     
  2. Thunder

    Thunder 3/4 ton status

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    If you are still running the TBI fuel injection set up you need ALL sensors and wires hooked up. FI will not run right unless everything is hooked up and operating. Without all the sensors the computer does not know how the engine is running and cant set fuel curves or timing. If it doesn't see readings from the 02 it just runs on a preset program. This program is just a limp home bypass mode. Your truck wont run very well and get horrible fuel milage in this mode.
    To hook up the 02 you need to drill a hole in your header and weld in a threded bung or nut the same size as 02 threads to screw the 02 into.
     
  3. cavscout19delta

    cavscout19delta Registered Member

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    cool how about the smog control?
    /forums/images/graemlins/1zhelp.gif
     
  4. rick88blaze

    rick88blaze 1/2 ton status

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    I haven't had a single problem since I put my headers and duals on last year on my '88 350TBI. I just took the belt off of the smog pump. I left the wires and vaccuum lines hooked up though. /forums/images/graemlins/thumb.gif

    Rick
     
  5. cavscout19delta

    cavscout19delta Registered Member

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    well i took everything off, it runs fine for a while then starts to surge. A friend said to change the fuel filter but it seems like timeing to me. /forums/images/graemlins/confused.gif
     
  6. dyeager535

    dyeager535 1 ton status Premium Member

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    Do you even know what "smog control" stuff you took off?

    Pretty hard to diagnose the problem if you say "smog control" and mean MAP sensor or something. AIR is one component, depending on what you are talking about removing, Thunder probably nailed it.
     
  7. cavscout19delta

    cavscout19delta Registered Member

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    [ QUOTE ]
    Do you even know what "smog control" stuff you took off?

    Pretty hard to diagnose the problem if you say "smog control" and mean MAP sensor or something. AIR is one component, depending on what you are talking about removing, Thunder probably nailed it.

    [/ QUOTE ]I took the smog pump and the lines that come out of the exsaust manifolds. As for the map sensor it has nothing to do with the smog crontrol /forums/images/graemlins/frown.gif
     
  8. dyeager535

    dyeager535 1 ton status Premium Member

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    I know MAP has nothing to do with emissions. (well, technically it does, but anyways) You didn't say AIR, you said all smog stuff, which is incorrect, and made it sound like you had no idea what you removed.

    AIR doesn't affect the ECM at all. You may have disconnected a vacuum line or dislodged a connector when you were in there though.

    If it were my rig and I was removing the AIR system, unless the rig is a rusted POS that isn't going to be re-sellable, I'd zip tie the wires back into a neat little bundle, in case A)they ever need reconnected, which might be the case if you move, or if you want to sell it to someone in a pollution control area, or B) you part the rig out and want to sell the entire harness.
     
  9. cavscout19delta

    cavscout19delta Registered Member

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    cool thanks for the info. no its not a pos and ive sank to much money in it now to sell lol. I called the chevy dealer and took it down to them the problem was the oyx sencor, which is now fixed. thanks again guys /forums/images/graemlins/thumb.gif /forums/images/graemlins/waytogo.gif /forums/images/graemlins/peace.gif
     
  10. R72K5

    R72K5 Banned

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    yes timing would be affected since the system is electronic timing control on these, and alectronic module under the dahs runs the timing of the ignition 80-up light duty under certain GVW rating
     

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