maf HZ ?

[frank1]

My car is acting kinda funny I plugged my loggger and its telling me that its reding 27~25 hz on idle
on my 1g usually reads 37hz
I noticed that my car when it runs 27 hz it runs crappy but it will go back to 37 hz and runs fine

Is my MAF going bad or is this an ECU Issue

 

[1990ggsxnj]

Have you pulled the ecu to check it? It's pretty easy to do and is one of those "simple" steps that can make a "big" difference.

 

[chucklesas]

Do you have an intake leak after the MAF? I would imagine that would throw the air count off.

 

[frank1]

I will check for boost and intake leaks

 

[frank1]

OK I checked for boost leak I only have a small one on the J pipe
I don't think a small leak can cause so much problems
I drive the car I feels like its pulls lots of timing I going to check my knock sensor
I also notice that I get 43 counts of knock ~ 3`4 rpms and it only does it when it wants to I figure its phantom knock

 

[stevep]

Quoting frank1:
My car is acting kinda funny I plugged my loggger and its telling me that its reading 27~25 hz on idle on my 1g usually reads 37hz
I noticed that my car when it runs 27 hz it runs crappy but it will go back to 37 hz and runs fine.

Is my MAF going bad or is this an ECU Issue



Remember that a DSM and GVR4 have different MAFs and that the airflow count for a GVR4 (MAF HZ) will be lower because more air goes through the bypass in their MAF than on a stock DSM MAF.

If you have a real GVR4 ECU that's taken into consideration. If your running a DSM ECU the lower air count can make the car run lean.

So to answer your question either or both could be a problem.

 

[frank1]

well am running the stock galant Ecu on the car the car is all stock
so you're telling me that dsm and vr4 maf sensors are different ?
is it not possible to run a dsm maf if I need it to ? /ubbthreads/images/graemlins/confused.gif

 

[prove_it]

You need to compensate for the change in sensors. DSM airflow sensors have a second honeycomb that the GVR4 doesn't. I know someone will chime in with the details shortly.

 

Yes, just remove the lower honeycomb, and your DSM MAS will flow like a GVR-4 MAS. /ubbthreads/images/graemlins/wink.gif
As Steve said, without the lower honeycomb, more air gets bypassed past the metered section of the MAS, which mainly effects the idle and lower airflows. This means that you *will* see a slightly lower Hz at idle on a GVR-4 than a DSM.

 

[chucklesas]

Quoting frank1:
My car is acting kinda funny I plugged my loggger and its telling me that its reding 27~25 hz on idle
on my 1g usually reads 37hz
I noticed that my car when it runs 27 hz it runs crappy but it will go back to 37 hz and runs fine

Is my MAF going bad or is this an ECU Issue



Somebody here has to have stock setup that can log their air count for you so you can compare to see if you're in the ballpark. Anybody?

 

[prove_it]

I'm using ECULINK V3, still have the factory MAF and I don't see numbers that low. I'm floating around the 35hz at idle. However, your idle speed and running temp make a difference. I do idle mine at 800rpms. It does seem that 25-27hz is a bit low. I would suspect a loose hose or vacuum leak somewhere.