Quote:
Originally Posted by mmm_2000
K, I checked the readings from the maf at idle. Nissan specs from the service manual says, at idle, warm engine Maf should read between 1-4g/s of air. Mine reads about 6-7g/s at idle. So I went and bought a maf from Kragen Auto, my cost 250 + core. I put it on and the engine runs perfect !!!! I stayed at idle for about 10-15 mins, engine feels great, no hesitation, fuel trims are perfect and the short trim is at around zero most of the time plus or minus 2-3%. I was so happy. i drove it arounf for another 10 mins up to freeway speed. And here is the "surprise":
Next day I try to start the car to go to work and the engine runs really really bad, idle jumps up and down from 300 rpm to 800 rpm and engine stalls after after like 10 seconds. I was so upset. Check engine light came on (p0100 - maf malfunction) as I checked it later in the day. How can a Maf go bad over night, with my car in the garage. Also here the temperature doesnt drop in the night below 50 degrees. I was getting late for work so I try to drive the car and I could not get the car at a higher speed than 30-35mph. So I dragged myself to work, knowing the auto parts store is next door and I can get a warranty replacement.
I got another Maf from the parts store after work, and with this same thing. I can barely keep the engine running, trying to rev it all the time and it chokes and so on. So then again I barely drive the car back to my house and I put my old Maf in and my car now works like before. But at least is driveable. Still rich at adle. I reset the check engine light and with my old maf it doesnt come back on.
Now I ordered a different brand maf and we will see if this works: beck/arnley. The original brand was Cardone. They are all remanufactured. The new one is about $430 !!!!!
Is it possible that the maf I bought went bad over night ???
And is it possible that the second one was bad out of the box???
My problem has to be the Maf, right ? With the first one my engine ran perfect, like it didnt in years. Perfect.
Im frustrated....
Tomorrow I'm receiving the other brand Maf and I'm going to exchange it again. Ill post as soon as I have the results. I also bought a stock air filter and Im not using K&N anymore.
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nissan oem filter right???aftermarket stuff in this case are no good either.
typically at idle speed the maf reading should be around the engine displacement in liters...therefore warmed up at low idle a 1.8l engine should be min 1.8g/sec maf readings. if its idling faster the maf reading will be higher.
Never had problems with bad maf replacement parts but have always used new oem parts. fingers crossed for you.
Nissan recommends entire maf sensor and body assembly replacement. Is the aftermaket maf just the sensor that unscrews from the body with 2 torx security screws?
Make sure the assebly its installed in the right direction or will give screwy maf readings to ecm (should have airflow arrow molded into it...think most nissans can only go on 1 way anyway).