MAF relocation

toofastlt1 · 10-07-2009, 10:23 PM

So i moved my maf from a such throught to a blow through and my car started idleing really bad. what do you think would cause this? Here is a crapy cell phone vid to show you what i mean. http://www.youtube.com/watch?v=L1HLZ65nEM4

AKS Racing · 10-08-2009, 12:01 AM

Idle surge from incorrect tune. Many of the SC'ed applications are set up with the MAF on the pressure side of the head unit vs the vacuum side. Proper dyno tune, and the surge should be handled.

toofastlt1 · 10-08-2009, 12:38 AM

when i plug the bypass valve it stops surging. does that mean its too rich at idle

AKS Racing · 10-08-2009, 03:54 PM

Where is the bypass valve located relative to the MAF? You can not bypass metered air (as in air that has passed through the MAF) back in front of the head unit, and expect the car to run decent.

The bypass inlet would have to be located prior to the MAF and discharge the air to the inlet of the blower. Even when doing in this manner, there is still a concern with reversion (air backing up) through the MAF.

Please provide details as to where the inlet to the bypass valve is in relation to the MAF location, and also include relative proximity between the bypass and the MAF.

toofastlt1 · 10-08-2009, 06:26 PM

the bypass valve is between the blower and the MAF so it hasn't metered the air yet. the Bypass is about 10 to 12 inches away from the MAF

toofastlt1 · 10-09-2009, 04:33 PM

sorry its only about 5 or 6 inches away. I still need help. could it be the tune?

rtracy · 10-18-2009, 08:45 AM

From my experience when ever you move the MAF from vac to pressure side your tune will differ. If I remember correctly I saw more air being read on the vac side.

toofastlt1 · 10-18-2009, 09:37 PM

so do you think its all in the tune?

Mo_Bandy · 10-22-2009, 01:45 PM

If you have the MAF on the pressure side of the SC it could be the turbulance of the air is causing the MAF to keep trying to correct... I have always found that the having the MAF on the vacuum side worked better... The only time I really had to do anything was when I went to the 8 rib I had to reprogram the MAF in the ECM so it would not set the over reference error.

I added a length of wire to the connector and ran the MAF and relocated it right behind the air filter just as it would be in a stock scenerio... As you probably know, as long as you are in closed loop the engine will compensate to get you to ~14.7 AFR once you are in open loop then it is up to your tune to get you to the probler AFR from there...

Hope this helps!

MO

toofastlt1 · 11-01-2009, 07:22 PM

hey thanks