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O2 sensor question

Discussion in 'The Garage' started by shane74, May 11, 2005.

  1. shane74

    shane74 1/2 ton status

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    Can a faulty O2 sensor make a rig run crappy?? Rough idle, running too rich, that kind of thing?
     
  2. 1979jimmy350

    1979jimmy350 1/2 ton status

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    yes it can. If your o2 is bad you run on a preprogramed fuel curve which is programed rich so you do not lean the engine out to much.
     
  3. shane74

    shane74 1/2 ton status

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    Well, that is about the last thing I haven't changed. It just threw a O2 sensor code this last time after I replaced some other parts. I'll pick one up and replace it. It runs like crap at idle (it wants to die) and can't hardly pull itself up a hill (knocks like crazy). It started a few weeks ago. I parked it and started driving the K5 till I could figure out whats wrong with it. It started all the sudden, like a bad vaccum leak. It only does it at idle. Once above 1500 rpm, it smooths out and runs fine w/ exception to the serious lack of power up hills. Starting to really irritate me. So far I have replaced the;

    cap
    rotor
    plugs
    wires
    electronic spark control sensor
    throttle position sensor (yes, I set it to the correct voltage)


    Oh yeah, I should mention that it's and '87 burb with a TBI 5.7/700-R4.

    Anybody have any ideas for me?
     
  4. 1979jimmy350

    1979jimmy350 1/2 ton status

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    when you replace the o2 sensor you might want to think about upgrading to a heated o2 sensor because they work alot better than the one wire ones
     
  5. shane74

    shane74 1/2 ton status

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    Good idea. It's all about the upgrades anyway, right?! :D
     
  6. blazerguy 90

    blazerguy 90 1/2 ton status

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    Replace the fuel filter.
     
  7. BurbinOR

    BurbinOR 3/4 ton status

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    Shane,

    Does that rig have a knock sensor? My TPI motor did, and it sounds like (from your description) it isn't working. I've got a scanner you can borrow for as long as you need it to check out some stuff. You can pick it up at my work if you want - I can bring it to work. PM sent to ya.

    By the way, if you need ideas on the three wire O2 sensor, let me know. Not a huge improvement in our area (doesn't get cold enough but any little bit helps, eh?).

    Frank
     
  8. shane74

    shane74 1/2 ton status

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    Did that when I replaced all the above parts. I knew I was forgetting something.
     
  9. shane74

    shane74 1/2 ton status

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    Is that what they refer to as a "Detonation Sensor"? If so, yes, I believe I do.
     
  10. ntaj*ep

    ntaj*ep 1/2 ton status

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    Put a vacume gauge on the intake, at idle what is the reading?
    Also what is your MAP sensor reading at idle?
     
  11. shane74

    shane74 1/2 ton status

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    I don't have one. Also, not sure where to hook it up to??

    I pulled the MAP sensor and had it tested. It tested out fine, so I didn't replace it. What do I need to look for?

    I do know at idle, the vaccum is low until it hits approx 1500 RPM.
     
  12. ntaj*ep

    ntaj*ep 1/2 ton status

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    I would put the gauge on the map sensor line (tee d into it) or at the vacume booster for the brakes. I would recommend you buy a gauge. Getting a good vacume reading will tell alot about engine issues. Leaks, valve issues, timing, ect. It will aid your correct diagnosis of the issue without needlessly spending more money.....

    **edit**

    Not so worried about the MAP itself but what the voltage is at idle. In other words if it is reading correctly or not.
     
  13. dyeager535

    dyeager535 1 ton status Premium Member

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    One of the few TBI codes I linked to is for the O2 sensor:
    O2 open circuit (code 13) Sounds like you got rid of that problem though?

    Scanner is going to help you out, sorry I don't have links to more of the "no code" troubleshooting stuff out of the manual. :(
     
  14. ntaj*ep

    ntaj*ep 1/2 ton status

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    How 'bout fuel pressure readings?
     
  15. shane74

    shane74 1/2 ton status

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    Those are good.

    Frank (BurbinOR) loaned me his Auto X-ray scanner today. I hope to get it figured out before the end of the weekend.
     

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