This POS car is really bugging me. Its not worth the money to take it to a mechanic anymore. Its not a bad car or engine but the previous owners were not kind to it. Anyway here are the codes its thowing:

Code #22)TPS voltage low/grounded
Code #34)MAF voltage low/grounded

The car sometimes starts fine and runs fine. Other times (50%) it will start fine and as soon as the tranny shifts into 1st gear (automatic) the SES will go on and the engine will start to idle really really rough and eventually die. When its idleing rough with the SES on the car seems to get bursts of fuel and stagger forward. Also on other occasions stepping on the brake pedal while in park will cause the SES to light up and also caasing the engine to idle rough. The engine never idles rough unless the SES is on. Here is what I have done so far to the car:

1)New air filter (cleaned entire air duct as well)

2)New fuel filter

3)Tried hitting the MAF gently too see if it malfunctions under vibration. It works fine when hit. I did this test when the engine was running smoothly.

 

SA,

The symptoms you describe may indicate a bad connection to the 5VDC reference source from the ECM. Several sensors share the same reference source. I'm not sure about the 231 Buicks, but most ThirdGen V-8s use the same ground reference connection for MAT, TPS, and CTS. TBI and SD cars also load the MAP senso on the same ground, and the 5VDC reference source is shared by both the MAP and TPS.

Your situation may be similar, and the MAF is apparently functioning correctly. I'd check the engine ground connections, and meter the reference voltage at both the TPS and MAF. You shoudl get 5VDC between the source and signal ground at each connector.

It is also possible that the card edge connectors at the ECM itself are not clean or seated tightly. You can remove the connectors and replug them several times. The wiping action of removing them and reseating them can clean the contacts and traces on the card to provide better connections. After almost 14 years, things like this can begin to happen. A little time spent repairing now can eliminate the problem for another 10 years or so.

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Later,
Vader
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"Let the bodies hit the floor!"
Adobe Acrobat Reader

 

Here is some more data I just collected. With the key in the ignition and turned to "ON" but without starting the engine I took these voltage readings. Voltages are with respect to the battery negative(black).

ECM connector to MAF:
Black-0V
Yellow-5.02V
Red-12.4V

ECM connector to TPS:
Black-0.02V
Blue-0.05V
Grey-5.03V

TPS output resistance:
Between Grey & Blue-6.85k(closed)/3.2k(FOT)
Between Blue & Black-2.56k(closed)/6.65k(FOT)
Between Grey & Black-5k(constant)

The TPS seems to be working as a Potentiometer(obviously) but Im not sure what the ranges should be. And Im not sure how I can measure the MAF directly. By the way, where is the ECM? I see a few black housings with wire harnesses but there are a few of them. Im on my way to get a new MAF, Ill just have to take it back if it doesn't fix the prob. I think it might be the MAF now that I cleared all the ECM codes and only #34(MAF) is being thrown now.