MAF Compensation Q
Thread Starter
Racer
Joined: Apr 2017
Posts: 434
Likes: 35
MAF Compensation Q
Hey Gang,
I have noticed lately that my cam miss has been a bit more than usual lately... a bit more of a miss feeling than normal...
So I decided to check the plug wires for loose connections...it seemed like one of the wires going to a coil was a bit loose and snapped into place more than it was...
While doing all of this I decided to clean the maf... in the process of this ...I noticed that the clamps holding on the CAI to the TB had come loose...not overly loose but I don't believe that they were 100% sealed prior to tuning...
I cleaned the maf... re-secured all of the clamps and took her out for a test drive.... it seems that normal not WOT driving seems to be considerable less responsive and slower than normal...
My Q is this....
I know that the MAF will compensate for up to 25% differences... If there were any leaks.... should the maf compensate for this?
Or should I reset the fuel trims??
Thanks...
I have noticed lately that my cam miss has been a bit more than usual lately... a bit more of a miss feeling than normal...
So I decided to check the plug wires for loose connections...it seemed like one of the wires going to a coil was a bit loose and snapped into place more than it was...
While doing all of this I decided to clean the maf... in the process of this ...I noticed that the clamps holding on the CAI to the TB had come loose...not overly loose but I don't believe that they were 100% sealed prior to tuning...
I cleaned the maf... re-secured all of the clamps and took her out for a test drive.... it seems that normal not WOT driving seems to be considerable less responsive and slower than normal...
My Q is this....
I know that the MAF will compensate for up to 25% differences... If there were any leaks.... should the maf compensate for this?
Or should I reset the fuel trims??
Thanks...
Le Mans Master
Joined: May 2016
Posts: 7,236
Likes: 1,546
From: Florida
MAF doesn't compensate for anything. It reads the airflow past it and the ECM uses that reading to fuel. If additional air enters into the air flow past the MAF then that is unaccounted for and will add to the air in the AFR.
Fuel trims can correct a lean condition up to 25% then report the problem in a CEL.
How/why are you going to reset fuel trims?
Fuel trims can correct a lean condition up to 25% then report the problem in a CEL.
How/why are you going to reset fuel trims?
Last edited by BlindSpot; Jun 10, 2017 at 06:05 PM.
Le Mans Master
Joined: May 2016
Posts: 7,236
Likes: 1,546
From: Florida
Fuel trims are self-correcting, that's what they do. If you pull the fuse, you'll start over, true, but will not correct anything. Assuming by reading your first post, you think the car might have been tuned with an air leak? The tuner tuned in an air leak? That could be a problem, if so. Correcting the air leak now will change fueling depending how the tuner set up the fuel. If the car has a MAF only tune, then yes, you'll especially have a rich fueling issue.
Last edited by BlindSpot; Jun 10, 2017 at 07:09 PM.
Team Owner
Joined: Nov 2007
Posts: 24,035
Likes: 2,342
From: Gilbert AZ
As Blindspot said, there is no maf compensation. Fuel trims can compensate up to 25%, but they also are based off narrow band o2s, and won't trim negative at WOT or read at WOT properly, so it won't adjust it properly for PE. It will apply positive trims at WOT, but if you clear those, and then go around beating on it, the car could be extremely lean.
At idle/part throttle fuel trims can adjust for some changes, but should never be relied on to do that.
At idle/part throttle fuel trims can adjust for some changes, but should never be relied on to do that.
