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Old 08-24-2007, 02:04 PM   #1
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Default maf reading to high setting code p0171?

at idle my maf is reading 16.4gpm i think this is to high i believe it should be between 8 and 10gpm. can anyone help on this
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Old 08-24-2007, 03:05 PM   #2
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I'll move your topic to the Mechanical section for you. This section is for performance related topics (adding power or new ideas).
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Old 08-24-2007, 05:20 PM   #3
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BillBoost37 had that code for some time, that I believe he tracked down to a bad ground. You may want to start off with a search for that code with him as the author. This is the diagnostic flow chart for that code. P0171

Edit - I checked mine tonight, and it was reading right around 5 g/* at 860 RPM, with the engine at operating temperature.
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Old 08-26-2007, 01:51 AM   #4
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I cleaned Maf, ground cable and check if spark plug wire was touching o2 wiring. lite stayed off for a day an a half then back on. Car has started shutting off especially if you accelerate then suddenly close the throttle.
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Old 08-26-2007, 02:11 AM   #5
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Did you perform any of the tests that were in the link provided? Check for vacuum leaks and fuel pressure?
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Old 08-26-2007, 11:45 AM   #6
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checked for vacuum leaks checking fuel pressure in a few will report back
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Old 08-27-2007, 04:31 PM   #7
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Checked fuel pressure 37 to 38psi even with the vacuum off the regulator. as soon as the engine is shut off pressure goes to 0 psi in less than 5 seconds. i just got this pump from zzp in june. this is my second one from them, the other one at least lasted a couple of years but at 2 months and no warranty this pisses me off. I will get one from some place else this time.
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Old 08-27-2007, 04:42 PM   #8
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FP should be tested without running the car for the baseline against the FSM. However if you only see that pressure idling...there is an issue.
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Old 08-27-2007, 04:56 PM   #9
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I agree with Bill. See what readings you get following the testing procedure. Hook up the gauge, turn the key on to have it pressurize. Bleed the air out of the gauge, then turn the key off and on (waiting about 5 seconds between cycles) and see what the maximum reading is. Specs say 48 - 55 psi, however with my Actron gauge, it seems to read about 43 or so, even with a new pump. From whatever max you get, it after turning off the key, it should not drop over 5 psi in 10 minutes.
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Old 08-27-2007, 07:32 PM   #10
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did pressure test with ignition on. I purged the gauge did another test, gage went to about 25psi then quickly back to zero which would explain my hard start.
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