greetings. code 100 popped up 2 day and turns out its a faulty maf. been having some idel surges. did a search and it pretty much seems that i will have 2 replace it.

called the dealership and tgey said 421.00 4 a new 1?!. thats insane. i was looking at hjte z06 conversion or maybe just a remf one. someone mentioned unplugging the maf and leaving it on speed density mode? can some one explain 2 me what this is, and is it any good/harmful? thanx. R.C

 

P0100 is "MAF insufficient signal activity". Check the harness connector to make sure you have +12V on the pink wire. It isn't real unusual for this wire to develop a break at some point, and require replacement.

If you decide you need a replacement.... do NOT under any circumstances pay dealer list prices. Dal Slabaugh or Jason Cromer will give you close to 50% off list on many items.

The Z06 conversion is also a low $$$ fix. But check the power supply to the sensor first.

 

thanx injuneer. i c what u mean. i unplugged the maf and cleaned it up a bit, nothing harsh. the pink wire u said 2 check,what can i use? dont have any scan checks or voltage equipment. also what does that speed density mode mean/do.?

oh and hell yeah on paying dealer price, f@*k that. thanx bro. peace. R.C

 

You need a volt meter.... cheap ones are less than $10. A decent digital multi-meter will only cost you $35.

The stock 94-97 PCM uses the MAF sensor to directly measure mass-air flow. That way, any "breathing" mod's that affect volumetric efficiency (intake, exhaust, heads, cam, RR's, etc) will be compensated for without reprogramming. Speed-density (93) on the other hand, calculates the mass air flow by measuring air temperature, air pressure, and rpm, and then looking up the "volumtric efficiency" in a table. The end result is the same as what the MAF sensor would have measured directly. But only if the volumtric efficinecy table is kept up to date, to reflect "breathing" modifications.

When you unplug the MAF sensor in a 94-97, the PCM defaults to speed-density. No real difference in operation should be noticed. The PCM is just getting its data from a different source. But, if you have serious mod's, the stock volumtric efficiency table isn't going to work very well.

So... you could save money by not replacing the MAF sensor, and driving around on speed-density, with the SES light staring you in the face. But if you have any real mod's, it just isn't going to run as well, and may require some reprogramming of the VE tables.

 

Injuneer, should the MAF pink wire have a +12v when the cars running or only after going into closed loop? I'm having the same problem, and I started my car, and checked the pink wire at the MAF and got 0v.

 

You should have voltage any time the key is ON.

 

Thanks for the info. Should I be able to cut, re-run and soilder a new wire in place?

 

Sure, if you can locate the problem.

 

Only real thing I can do is test the wire close to the PCM, and if i got good +12v there.. So fun.. It's like I fix something every week on this thing..

 

The pink +12V power wire to the MAF does not come from the PCM. It comes from a fuse in the dash panel. You need to verify that there is a reliable +12V at the pin on the MAF connector. The only wire on the MAF that goes back to the PCM is the yellow signal wire.

 

While the power for the MAF does come from a fuse inside the car, the same circuit also feeds a couple of pins going into the pcm. The circuit is branch spliced inside the engine harness.

 

Stupid F*&#@NG fuse under the hood. Glad I decided to check that before going on with tearing out the wire. heh.

 

Well, whatever my problem is, it's still there. I'm gonna go out and check alot of stuff.. The fuse underhood that blows is labeled "ENG SENR" or something to that effect. It takes out the MAF and all o2 sensors. Been tring to track down what else it feeds with my crappy Chiltons manual.