unplugging the maf, possably bad maf

[viridionplague]

so ive been trouble shooting some issues, after doing a compression test i started getting some choking and stuttering as soon as the car started creating a positive pressure in the intake. around 3000 rpm. for some reason 3rd gear could boost till around 4k rpm before having problems.

sometimes its like its boost leak/fuel cutting, other the exhaust pops alot and bogs out.

boost leak test we fine, just a small leak around the throttle body, i had this before i started having problems and it was just fine though.

so after searching i read about unplugging the maf sensor, of course i tried this, just around the block quick because i didnt want to hurt anything.

and what do you know the car runs perfect, boosts just fine, only went to about 4500 rpm in 2nd and 3rd, and never full throttle.

so im wondering if anyone else might think this is a bad maf sensor, or if it might be something else.

and how does the car run without the maf plugged in?

 

[360glitch]

I'm wondering about my MAF as well. I have idle surge and I've tried everything to fix it. After a boost leak test the other day I started the car up and had forgotten to plug the MAF in and there was no surge. Of course, after I plugged it in it was back. Could this be a sign of a bad MAF?

 

[tkelly27]

No. When you unplug the MAS the engine will enter a primitive form of speed density (known as AlphaN or Alpha#) where it calculates fuel flow by TPS and RPM alone. This is pretty much ok for it to do up to about 4500rpm and at low throttle positions. This is because you are pretty much not in boost for a vast majority of that.

Do a boost leak test. Do an intake leak test. I actually plug my boost leak tester into where the MAF goes and do them both at the same time. A pre-maf leak is as bad as a boost leak.

Welcome to the world of draw through mass air sensors.

 

[360glitch]

No. When you unplug the MAS the engine will enter a primitive form of speed density (known as AlphaN or Alpha#) where it calculates fuel flow by TPS and RPM alone. This is pretty much ok for it to do up to about 4500rpm and at low throttle positions. This is because you are pretty much not in boost for a vast majority of that.

Do a boost leak test. Do an intake leak test. I actually plug my boost leak tester into where the MAF goes and do them both at the same time. A pre-maf leak is as bad as a boost leak.

Welcome to the world of draw through mass air sensors.

I am not saying you are wrong, but did you mean to say a pre-maf leak is as bad as a boost leak. Were you meaning post maf (but pre-turbo)? Just curious...

 

[tkelly27]

Yes, you are right. Pre-turbo, post maf. It's been a long day, I've been tracking those down the whole day.

 

[360glitch]

Yes, you are right. Pre-turbo, post maf. It's been a long day, I've been tracking those down the whole day.

I understand, it's been a long one for me as well. Thanks for the help.

 

[viridionplague]

well im planning on buying a maf-t setup, ill let you guys know how that goes.

the way i figure it, injector problems and ignition problems would still exist if that was one of the problems.

boost leak has been eliminated via boost leak testing.

so im pretty sure that its either the sensor itself, or a pre turbo leak. either way a maf-t setup in blow through would kill either problem at the same time

 

[92blacktsiawd]

Have you figured out your problem? I have the same problem with my talon right now. just wondering