My car is missing (coil wire arcing to water pump) and had a MAF code. So I got a used MAF(it came with a 90 day warranty.) I installed the MAF and it still setting a code.

Would a misfire cause a MAF code. I mean if it's not burning the gas then it's going out with the exhaust. Wouldn't that make the O2's read rich? If so could that be why it's saying the MAF is bad? Like it's not metering the right amount of air for the amount of fuel in the exhaust? Thanks

 

Its probably the harness.. more specifically the plug on the harness. I think its a common problem on Fbodies. Same thing happened to me and Ive seen ppl complain about this before and its usually wiring in the plug.

 

As noted above, could be loss of power to the pink wire on the harness connector. This is fairly common with the 97's for some reason, not as common on the earlier cars. Key on, pull the harness connector off and probe the pink wire for +12V.

The only real "check" in OBD-I diagnostics is for power to the MAF. There's no way anything else - like a miss - would cause problems. The MAF just tells the PCM how much air is entering the engine. After that, other systems take over to control the fuel and the A/F ratio.

You can also check the output signal from the MAF. Its a variable frequency, ranging from about 2,800Hz (10 gps) at idle to about 9,000Hz (239 gps) at WOT/max rpm on a stockish engine.

 

You mean the 3 prong harness that actually plugs into the MAF, right? I'll have to check it. Does it usually corrode or just need to be replaced.

 

Yes.... the connector from the harness to the MAF sensor. Make sure the pins aren't bent. It doesn't usually corrode. In the 97's, something causes the pink wire to break further back in the harness.

 

I'm getting 11.8v on the pink wire and 4.8 on the white.

 

Is it possible the arcing is also reaching the MAF harness? That would screw the frequency output signal up pretty baddly.

 

In the b-bodies anyway the single most common cause of MAF codes is the AIR system going bad and water backing up into the airfilter box and getting sucked through the MAF. Not entirely sure what the stock f-body intake looks like so I don't know if this is even possible in them but worth a look.

 

When it was scanned it said it had a AIR pump problem as well. What exactly is that. I've never really seen or heard much about it.

My SES light started coming on about 3 or 4 weeks ago. Then it started missing about 2 weeks ago. When I took it to get it scanned, it pulled an MAF code, and AIR pump problem, and a EGR valve problem.

 

Somewhere after the air filter and before the MAF there should be a 1" diameter hose that runs to a black plastic pump on the engine, that pump then pumps the air into the big "U" shaped tube that hugs the front of the motor and then routes the air into the exhaust manifolds. Basically this is an electric "smog pump" as many used to call them on older cars where they were belt driven. What happens on the b-bodies anyway is the vheck valve by the manifold goes bad so exhaust gets back to the pump when it is off, the water condensates out of it and fills the pump with water. Later on you get aggressive with the throttle and exhaust backpressure and intake vacuum conspire to draw water up out of the pump into the the airfilter box where it is then sucked through the MAF. It does not actually damage the MAF but the resistors getting wet will cause things to go out of range and the pcm to set a MAF code.

 

Ok guys..im having the same problem.. MAF code and the car is stublng at idle. so in my service manual it said to connect the voltmeter between harness connector terminal "A" and ground. It then says that it should read between 4-6..and mine was 5.4! Is the same way you all are checkin yours or is there a different way?? Thanks guys.

-Josh

 

Anybody?? Need some help..cant stand not having the car to drive!!
Thanks Fellas.

 

I just got my Taylor wires today. I didn't have time to change all of them. So I just put the coil wire on to replace the original one that was arcing. The Taylor coil wire started arcing immediately. I can't tell you how P.O'd I am right now. Is there anything that can cause this besides the wire. Like to much resistance or something. They seem like great wires but I mean it's like I never swapped the wire with the new one. Still sputtering. On your cars does the end of the coil wire that goes to the OPTI lay against the water pump?

 

One way to rule out the MAF is to just unplug it... the computer will then run in whats called speed density mode like all the aftermarket FAST computers use as well as the 92-93 LT1s.

If the problem persists then you know its not the MAF.

 

So running the car without the MAF hooked up wont damage anything??