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Thread: rpm drop help

  1. #1
    Potential Tuner
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    Aug 2011
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    rpm drop help

    since turning boost up my car has been basically falling on its face about .6sec into run not sure it its running out of pump or injector or something else. has 2 bosch 044 and 127 fic injectors, 347ci 80mm turbo, powerglide. here is one pass that did it bad and another when I turned the boost down, any help would be great.
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  2. #2
    Kinda seems similar to what my car was doing before I found out it was running Donald Trump rich (Like 0.60 lambda). But a lean condition could produce the same results I guess. Is this on 91 octane or e85?

  3. #3
    Senior Tuner
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    You have a boost controller? Is it programmed with ramp rates? If your talking about what I think I am seeing looks like your boost controller.

  4. #4
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    I run c16, yes I have a boost leash controller right now it's on no delay. One stage.

  5. #5
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    I see, so its you coming up on the brake, hard to tell with no speed input. Your scanning to many useless pids and it cuts down on resolution. You are out of injector on both runs. Get rid of all the misfire data, afr commanded lo res, both iac, ignition voltage, dynamic airflow, knock learn factor, both ltft, crank sensor current. Do another log and might see a little more, its why your injector duty cycle is so jagged.

  6. #6
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    If I am running out of fuel pump or pressure would it cause injector duty cycle to go up? I should have plenty injector.

  7. #7
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    You are running olsd. The computer is doing what you told it to do, no feedback. So injector duty cycle will not go up because of lack of pressure. Now when you were tuning it, if you increased your ve table and did not get the responce out of it you expected on the next run, that would point to being out of pump. Run another log with stuff taken out I suggested. Hopefully increased resolution will allow you to see more.

  8. #8
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    Okay, my map was consistent until I tuned up boost, that's where this started happening and I have added fuel and still lean maybe that's the problem. I'll get another but will be this weekend was hoping to try and fix before I waste another trip to the track

  9. #9
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    Log or moniter fuel pressure on your run, easiest way to confirm pumps.