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TBI idling probs.

Discussion in 'The Garage' started by beater74, Dec 3, 2003.

  1. beater74

    beater74 1/2 ton status

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    i gotta TBI that is having some intermittent iding probs. most of the time it will idle just fine but occasionally the idle speed will jump up a few extra hundred RPM's for no apparent reason. it will start up fine and idle high when cold and drop down to the appropriate RPM as the engine warms up, but in the middle of a trip the idle speed will jump up and if i cut off the engine and restart it this will usually return the idle RPM back to normal.. got any ideas? /forums/images/graemlins/confused.gif
     
  2. fortcollinsram

    fortcollinsram 1/2 ton status

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    Hook up a scanner and see what is happening at the IAC and the TPS when the prob occurs. Also, check you EGR valve and for any vacuum leaks, esp at the vacuum hose to the MAP sensor

    Chris
     
  3. oldtoyboyd

    oldtoyboyd 1/2 ton status

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    The TPS sensor normally makes it idle at 2000 RPM when it goes out and will set a MIL light. The IAC motor will cause it to bounce around and will not set a MIL code normally. When it acts up you can normally unhook the IAC connector and it will stop if that is the problem. /forums/images/graemlins/k5.gif /forums/images/graemlins/k5.gif /forums/images/graemlins/crewcab.gif
     
  4. jjlaughner

    jjlaughner 3/4 ton status

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    I replaced my timing chain, very worn timing chain and it helped alot. I think it was tricking the motor into adjusting the timing bacuse of the slop in the chain.
     
  5. jjlaughner

    jjlaughner 3/4 ton status

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    I'm not telling you to run out and change the chain because its a huge pain! But its an idea if all else fells.
     
  6. florida4x4

    florida4x4 1/2 ton status

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    If you think it's a pain on a SBC then try any small block ferd. yuuucka! /forums/images/graemlins/thumb.gif
     

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