'92 TPI hesitating around 3000RPM

Discussion in 'Engine Topic' started by mrgunman, Apr 17, 2021.

  1. mrgunman

    mrgunman New Member

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    I recentyly bought a 92 Z28 and around 3000-3500, it seems to hesitate. The motor was rebuilt, drives fine when just cruzing but when I stomp on it, it acts up around 3000. The guy I bought it from says it needs to be tuned. I am talking to a guy who runs https://tunedperformance.org/. He thinks we need to datalog and burn another chip. Any ideas? Am I doing the right thing?
     
  2. ULTM8Z

    ULTM8Z Veteran Member

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    Is the engine stock?

    If so, it doesn't need tuning. Something is wrong and needs to be fixed.

    But dataloggging can be an effective way to diagnose those things though.

    If it's not stock, then yeah tunedperformance is a good resource. He's pretty well known on the thirdgen.org site.
     
  3. mrgunman

    mrgunman New Member

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    I think the guy put in a mild cam and bored .30 over. I think he said some about 270 lift on the cam. I think the guys name is Brian at the tunedperformance. Hopefully we can get it right. :-(
     
  4. mrgunman

    mrgunman New Member

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    Im also going to change the fuel filter. Looks pretty old.
     
  5. ULTM8Z

    ULTM8Z Veteran Member

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    Brian yep.

    Yeah make sure the rest of the car is up to snuff before embarking on tuning.

    The last thing you want to do is tune around other malfunctions... its a huge headache when that happens.
     
  6. mrgunman

    mrgunman New Member

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    What can I look for? It runs fine when just cruzing. Doesn't have any ticking sounds and idles pretty good. It does idle a little low in gear, around 500-600. Maybe the idle control needs to be replaced. Its a cheap part. I tried to reset the one in there now but didn't change. Maybe its getting stuck
     
  7. Ihada70Z28B4

    Ihada70Z28B4 Veteran Member

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    Try cleaning the MAF. Do some data logging when driving. Capture the hesitation and in scope type display look at the MAF readings for it dropping out.
     
  8. ULTM8Z

    ULTM8Z Veteran Member

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    '90 and up are MAP cars, so MAF sensor.

    Though I agree some datalogging could help pinpoint the issue. But other than that, just checking the basics... ensuring the ignition system is in good working order, fuel pressure is good, etc.
     
  9. mrgunman

    mrgunman New Member

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    Whats normal pressure for a 1992 Z28 with a 350?
     
  10. mrgunman

    mrgunman New Member

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    How can you test the MAP sensor?
     

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