Mass Air Flow Sensor/Fuel Pressure Problems
08-18-2005, 09:55 PM
#1
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Mass Air Flow Sensor/Fuel Pressure Problems
I need some help with my 98 v6 mustang, when i had the computer checked because of check engine problem the first thing it said was the o2 sensor behind the catalytic converter, but after replacing that it came with 2 different bank codes (P0171)which stated that the computer recognized too rich or too lean condition on one engine bank only,(too lean), and said to suspect fuel pressure or the Mass air flow sensor....or that was the first choice anyway, and this part is around 100 which i have a buddy who sells mustang parts off wrecked stangs so about half of that but i still dont want to spend that much on the sensor if it is something totally different...i recently replaced the fuel pump about 3 weeks prior to this and after this occurred i check the fuel filter and it was fine so i dont know what else it could be........ummm it sounds like a go cart taking off puttering and such and has about as much acceleration as one too.....it runs to about 60mph at its peak and then inconsistently the fuel pressure or rpms will fade where it cant even be revved past 2 rpms........any help would be needed in diagnosing this problem.....thanks
08-18-2005, 11:05 PM
#2
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RE: Mass Air Flow Sensor/Fuel Pressure Problems
Yes! It is your MAF. I gurantee it. Don't drive it until you get it fixed, learn to ride bus.
What you can do is clean the MAF sensor and see if it helps.
If you are going to get a new or used MAF be sure it is from the same model year and has the same P/N. Your computer is calibrated to a specific MAF function, if you get a different MAF a different calibration will have to be done to your computer, expensive.
Here is what a MAF transfer function looks like.
It's a look up table for converting reference voltage to the flow. IMO it isn't very accurate, I prefer manifold pressure instead.
AL
What you can do is clean the MAF sensor and see if it helps.
If you are going to get a new or used MAF be sure it is from the same model year and has the same P/N. Your computer is calibrated to a specific MAF function, if you get a different MAF a different calibration will have to be done to your computer, expensive.
Here is what a MAF transfer function looks like.
Code:
MAF Voltage / Flow kg/hr 0 10.75 0 10.75 0 10.75 0 10.75 0.571044921875 10.75 0.75 14.75 0.884033203125 18.75 1.091064453125 25.75 1.181884765625 29.00 1.321044921875 35.25 1.468017578125 42.75 1.573974609375 49.25 1.69091796875 57.50 1.802978515625 65.00 1.889892578125 71.25 1.989013671875 79.00 2.154052734375 94.75 2.31591796875 112.25 2.449951171875 127.25 2.58203125 144.00 2.694091796875 159.25 2.909912109375 192.00 3.14892578125 233.25 3.35498046875 274.25 3.5439453125 315.00 3.885986328125 394.25 4.177001953125 470.25 4.443115234375 548.75 4.76806640625 659.25 15.999755859375 659.25
AL
08-19-2005, 07:32 PM
#3
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RE: Mass Air Flow Sensor/Fuel Pressure Problems
*%^&%R^#$ yea i cleaned the sensor wire with alcohol even tho it looked clean and yea it didnt help as i guessed and was alright to begin with......is there any way of telling by lookin at the actual MAF that it is actually the problem? i mean if im goin to spend around 100 i might as well jus save up a couple hundred more or so and jus get CAI or new air filter .......any help would be appreciated..thanks
08-21-2005, 07:50 AM
#5
Join Date: Aug 2005
Posts: 3
RE: Mass Air Flow Sensor/Fuel Pressure Problems
Had a Mass Air sensor go bad on me in a different car. I had the same symptoms you are describing. It turn out that there are fine wires inside the Mass Air sensor that vibrate when the air goes by them. No way to rebuild. If money is an issue I would try swapping one with someone who has a good one. Drive it and you will see the difference right away. Hope this helps.
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