Erratic engine - need a little help

[BigRick74]

My 93 explorer is doing the same thing. Still working on it.

 

[BigRick74]

Thanks u guys

thank u guys this is 1 great site

 

[awood]

Lets see if I got this right...The connector on the MAF has four wires, and it's clearly labeled A, B, C and D. If you use a pair of T-pins, or a couple of sewing needles, you can back-probe the connector while the engine is running. At idle, you should have battery voltage between pin A (battery voltage after it goes through the PCM power relay) and pin B (ground). If you don't get this, you have a bad PCM or wiring. Then, remove your meter leads from A and B and then back-probe pins C and D. (signal return and MAF respectively). You should have around .5 to 1.5 volts. As you increase throttle smoothly off idle, the voltage should increase smoothly too, but no more than 5 volts at full throttle. 5 volts is the operating voltage of the PCM. If you don't get these values, your MAF is probably bad. If you DO get these values, it could still be a PCM, or wiring. Try Googling different key words to confirm these test procedures. There's several places online that describe this test.

Please confirm this with your wiring diagrams, and use a Digital volt meter, not an analog meter.