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guess the sensor issue time!
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Old 07 Jun 2013, 08:04 PM   #1 (permalink)
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guess the sensor issue time!

hey kids! LONG time lurker, years in fact.. I have an issue now that I can't solve.

02' WRX stage 3 COBB, VF34, OS MAF. ect. no problems in over 150k Km then one day in early winter car just went to shite..

Picked up a massive misfire across all cylinders, changed plugs and misfires reduced but stayed, coils checked out, sea foamed internally and through fuel.. after a few months of driving and paying close attention to the car I've narrowed it down;

Open loop is fine call it 90% ( out of a possible perfect 100% where the engine is working at optimal), my gas mileage is more then double in open loop and I don't get any misfires/flashing CEL.
Cold start acceleration and enrichment seems to be 'good' not perfect call it 70%.. where the problem lies is in closed loop- engine warm" ~30% drive-ability.
Tip in bogs down, back fires during static load & load situations, plus popping concurrent with over fueling and of course SHITE mileage, were talking 1/4 tank or more usage in under 30 miles.

So my question is, which sensors should I be looking at as the primary cause. I DO have a C-west hood that has open venting right over the MAF sensor, I've cleaned the element with no joy.

Thanks in advance guys.
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Old 08 Jun 2013, 06:37 AM   #2 (permalink)
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Re: guess the sensor issue time!

Nps checked ?
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Old 09 Jun 2013, 12:39 AM   #3 (permalink)
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Re: guess the sensor issue time!

didn't think of that, is there a non shop based way to check it.. besides replacing it ?
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Old 09 Jun 2013, 05:34 PM   #4 (permalink)
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Re: guess the sensor issue time!

cheap OBD lead and laptop
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Old 10 Jun 2013, 04:21 PM   #5 (permalink)
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Re: guess the sensor issue time!

Idle is lumpy and missing as well, so i don't think it's the NPS. Really it sounds like ass right now.

I'm going to replace in order: intake press sensor, MAF, tps, NPS. since it runs fine in open loop I may just adjust out closed loop and run full open loop..

anyone done a full rpm open loop ? downfalls? drawbacks?
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