Quote:
Originally Posted by blue62
Your current snapshot and the fact that you have hesitation under load suggest a vacuum leak.
I would buy a vacuum gauge (about $20.00 at most auto parts store). and do an intake vacuum test. Should read 18-22 on the gauge with a steady needle at idle.
That will prove out yes or no on the possibility of a vacuum leak problem.
If you suspect a faulty MAF sensor unplug it. Take the car for a short drive and see if that improves engine performance. If it does then the MAF is faulty, if it doesn't then most likely the MAF sensor is not the problem. But the wiring to the sensor could be.
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I checked vacuum from the brake booster hose. It was slowly waving up and down between 17.5-18”. Is that acceptable? I did another smoke test and couldn’t find anything.
I unplugged the MAF, didn’t drive it but just revved in the driveway. Seemed to improve but still showing lean condition (you add the numbers together correct?) When revved to 4,000 rpm:
Stft1 -14.84%
Stft2 -16.41%
Ltft1 +31.25%
Ltft2 +31.25%
I removed the MAF and it is a Bosch unit. Looks to be in good shape visually. Not sure how to tell if it is genuine Porsche part or aftermarket Bosch. .00 end of part number so it is not the newest version .01.
I took MAF readings at various rpms and it is a straight line when graphed.
800 4.25 g/s
1400 6.00
2200 9.5
3000 12
Where do I go from here??
Would an exhaust leak affect both banks?