texas97z

All right, really need help on this one. Car is flooding out. Code came back mass air flow sensor so I replaced with rebuilt unit.No improvement. I changed the spark plugs and got a little improvement but car still only runs when giving it about half throttle.Any less and car will die. Have not been able to re run codes as buddy with scanner hasn't been able to come back over. As far as for fuel related issues, fuel pressure came back with 42 psi at idle 45 psi at mid load and 55psi at full throttle. Nothing out of wack there. Car is tuned for the mods listed below and was running like a champ before the mass air flow. Please help, I am really frustrated.

dangalla

i could be really off here but maybe try unhooking the battery to clear the kam

Severous01

check for pirate air...vacuum leak, open hose AFTER MAF...

try unplugging maf and running, if you're still having problems it's not the maf.

1SlowFormula

Something to try that will help troubleshoot this is to unplug the wires going to the MAF, if it drives better then it is the MAF or wiring, if not there is something else you will have to start looking into...

Injuneer

What was the EXACT MAF code? There is more than one. That may tell us more specifically what the problem is. If it was P0100 it might indicate either the MAF sensor electronics were deceased, or that the MAF is not getting +12V power from the pink wire on the harness connector. A broken pink wire is a common problem on the 97's for some reason.

There is also a code for an irrational number from the MAF, when compared to the PCM's speed-density calculation of mass air flow rate.

Unless you are running an AFPR, your fuel pressure looks too high. Normally you will see less than 40psi at idle with the vacuum compensation line on, 41-47psi with the vacuum compensation line off. Then at WOT/max RPM you should see about the same pressure you saw with the vacuum line off. 55psi is excessive, and would cause the injectors to flow about 12% more fuel than the PCM thinks they are flowing.

texas97z

ok, unplugged the mass air flow and still did it.What do you think it is? Again car is running real rich and flooding out the engine. And I tired clearing the codes by unplugging the battery and holding the two together for about 30 seconds. Did not clear the code. If it was still throwing the code,would that cause the problem?

texas97z

stock fuel pressure requlator.

texas97z

it said MAF out of range.That's what my buddy said who read the scanner said. I wa at work when he did it.

1SlowFormula

Well if you have a chance to have someone look at your ECT (Engine Coolant Temp) sensor in the water pump. It's a key component in telling the PCM how much fuel to pump through the injectors. If it goes bad, it will cause an extreme rich condition.

Injuneer

GM has codes for several different problems:

P0100 - Circuit malfunction (static frequency) - sets when there is no frequency change of more than 2 Hz between successive reads, after looking at 4 consecutive reads in a row.

P0101 - System performance (rationality) - MAF mass flow differs by more than 25% (high flow conditions) or 40% (low flow conditions) from the PCM's calculation using speed-density.

P0102 - Circuit low frequency - MAF frequency less than 1000 Hz

P0103 - Circuit high frequency - MAF frequency exceeds 10,700 Hz.

You can check 0100, 0102 and 0103 with a multi-meter that reads frequency.

Did you check for +12V on the pink wire?

You held two "what" together?

CamaroSS8887

how do you fix the p0103 code and 100

Billy18bm

TTP. Im having this same issue.