I had my datalog read, and he said I either have a bad maf, pcm, or the pcm grounds. He said the maf is pulling way to much air. Equivelant of a decent sized camshaft. how could I diagnose if it is the maf or not. I unplugged the sensor, but it drove the same. Where are the grounds for the computer located, and numerous times when connecting, disconnecting the battery, I have had some big sparks at the terminals. Could that fry my computer?

 

Sparks are normal look on shbox.com for the location of the grounds. can you post your datalog?

 

I dont have it, or id post it. Bryan herter looked at it, and said everything looks good, except maf readings. He said it was pullin in way to much air, and said one of these three things could be the culprate. I was drivin around earlier w/o the maf plugged in, and the car ran maybe a little better, but not like It used to

 

could a bad maf cause the car to have no low end power at all? if I unplugged it, what would happen?

 

Yes it can, if hes right it would run rich. what would happen if you unplugged it? it would first off switch to speed density mode (using map sensor) and secondly it would kick into limp home mode, and pull timing/run rich to keep from burning the engine up.

 

thanks for the help. I guess I do need an maf sensor

 

If you disconnect the MAF it simple switches to SD. Not limp home/pull timing.

 

It spits out a check engine light which puts you in limp home mode

 

Wrong. As usual. RTFM.

 

Really now? so then whats error 48? MAF System Diagnostic error...

 

Now go RTFM and find out what action the PCM takes when DTC 48 is set.

You are doing a great job of maintaining your status as the single worst source of tech info on this forum.

 

I am no expert, but dont some run purely speed density, and have no problems with limp home. Even the 93's ran only with speed density, so I dont see it putting the computer in rich mode.

 

speed density doesn't put it into rich mode, having a sensor fail does.

 

You have provided nothing to this discussion. If you unplug the MAF and do not tune out the error codes the engine will throw a CEL and pop on the fans. That usually means limp home mode. Yes it will continue to run fine, no it won't blow up. But your fuel economy is going to suck and it ain't gonna run right, especially if you have changed ANYTHING on the induction or exhaust. If your airfilter is clogged up and needs to be changed its going to run ****ty if your MAF is descreened, its going to run ****ty. The SD tune is for a stock engine with full emissions equipment so if hes changed anything on the exhaust or intake its going to run ****ty, hell I wouldn't be surprised if using a fram paper filter instead of an AC Delco paper filter caused a minor change to the volumetric efficency of the engine.

 

My MAF is disconnected, and the only difference is it that the engine runs in speed density mode. Pretty well, too... definitely not limping. Rich mode...?