Thread: Maf failure

Anyone experience MAF failure on their blow-thru setups? I'm hunting an issue right now, but it's going to be a few days before I get datascan hooked up to do some testing.

I am hunting down my bog issue at 3000rpm. Recently, it has extended and become intermittent. Sometimes it bogs all the way to 5k. It goes full rich during the bog and blows black smoke.

So I have been finding that this bog issue is rather severe when the engine is warming up. When the needle is 1/8th the way up the bogging is obnoxious. Once the engine warms up to 1/2 it clears up immensely.

I have determined that this maf may be slowly going out. Typically when this happens the car won't run at all. I am hoping to catch this issue before it fails completely and leaves me stranded somewhere.

Anyone have a maf fail on a blow-through setup? If so, what are your symptoms?

I imagine if this comes to a maf issue it could be the rotation of the maf in relation to the bends in the intake pipe, and that issue may be easily cured.

What is your minimum MAF voltage? Are you running in limp mode? If you're lower than 1.0v that could give you problems. Some of us drop the minimum voltage down to .9v as added insurance to keep the MAF from running rich at idle. Just a thought.

Idle is fine, maf voltage has not been checked yet. Waiting to datascan it. But it seems right now to only run really rich around 3000rpm-4000rpm.

I had that same problem when I had a massive boost leak at my bov o-ring. It would bog and go dead rich from 3-5k and then just BAM, power kicks back in hard and a/f still rich but no bog. Once I fixed the leak, all was perfect.

I see your using an adapater plate for your maf, I never liked using those especially on boosted setups as they seem very prone to leak. Maybe do what I did and cut the flange off the maf housing and put a coupler straight onto the maf. Again it could be a maf problem but seems like a boost leak.

You could try taking it off and clean the hotwire with some maf cleaner really good. Ive seen oil film get on there before and it causes issues.



Cut the flat face part off leaving a lip to act as a bead and you will never have issues with leaking or blowing couplers off.

What he said! Mine was a boost leak not to long ago but.was way worse.then yours. Found out I had a huge crack along the bottom of my maf. If u feel its the filaments itself I still have mine if u want. Housing is done but sensor is.good....

I call boost leak as well. Check your piping, bov etc.

Well, you guys have seen my setup. Blow thru, maf is 14" from the throttle body. Nothing in-between. I guess it could be an intake manifold leak... but I doubt it, since spraying brake cleaner in that area yields no change in idle.

I deleted all vacuum hoses from engine, even the pcv valve. Yet it still has that nasty bog at 3k. I disconnected the CTS and it didn't do anything. I am working my way to the maf. I cleaned it just now, checked for leaks around the maf. The adapter on the maf could be leaking, but it is also before the sensor. I don't think it is leaking though.

I am hoping for a boost leak somewhere. I am going to find it eventually.

perhaps the bov diaphram is leaking? where the vacuum source is.

maybe you cracked the housing ? sometimes those tops of the z32 mafs pop off or become really loose and can leak

Well, I won't know if this has fixed the issue until tomorrow. I cleaned the maf yesterday, took her for a spin just a minute ago and it ran perfect. No bogging.

I know there is a bit of a leak on the wastegates, I'm just not sure how/why/where on the wastegates it is leaking. It is a very very small leak.