New MAF install question

[ReplayMan]

I swapped my OEM MAF for a new 75mm Pro-M Bullitt today. FYI my 91 LX is stock. I didn't disconnect the battery, just a quick swap. And, the car has a hesitation in low gears during acceleration. I realize the ECU has to learn...but how many miles does it take? I drove around this morning, but it still has this hesitation.

 

[notchback]

i'd unplug the batt to reset

 

[ReplayMan]

Now I unplugged battery...re-installed. It runs poorly, gets better as I drive. But still has that hesitation. How many miles does it take?

 

[tannerc91gt]

What size injectors is the MAF calibrated for? What intake/TB are you using?

 

[ReplayMan]

Everything is stock. Meter is for 19s.

 

[jrichker]

It can take up to 30 minutes of driving under varying conditions for the computer to re-learn the settings for a new sensor. For best results don't just drive around the block or on the highway, do different kinds of driving.

 

[Three50won]

Maybe the heater wires in the housing are dirty. Get some MAF spray cleaner and hit it a few times, let it air dry (only takes a few seconds), and then hit it a few more times...see if that helps.

 

[ReplayMan]

It works great with the OEM MAF, no problems.

 

[Beasty306GT]

the mass air might be dirty or defective

 

[ReplayMan]

Brand new - re-calibrated.

 

[Three50won]

Not the wires that connect to the sensor, I meant the wires inside the actual housing. If you look through the MAF you'll see tiny wires. If they are dirty then they won't be able to correctly measure incoming air...They may have gotten dirty when it was packed and sent to you.

 

[ReplayMan]

What is MAF spray cleaner?

 

[jrichker]

To clean the MAF element, remove it from the MAF housing and spray it down with electronic parts cleaner or non-inflammable brake parts cleaner (same stuff in a bigger can and cheaper too).

 

[ReplayMan]

OK, I got the answer for my problem. I hope this could help others out there.

Just spoke to Chris owner/calibrator at Pro-M Racing. The problem I am having, is the "position" of the meter/sensor.

When Chris calibrates the meter, he uses the exact same cold air tubing. But, the problem is, there is no bracket to fix the Pro-M meter in my car, so it is in same exact position as when it's calibrated. I had the meter clocked too counter-clockwise or closer to 11'oclock. It has to be exactly level/12'oclock to get the precise air measurement. I clocked the meter a bit and the car runs smooth.

Chris also stated, the elbow on the BBK CAI causes air to flow heavier on the outside of the tube (closer to the engine). And, less air on the inside (closer to the fender). These older sensors have to be exactly dead center. One advantage...if I wanted to run a little richer, I can have the meter clocked clockwise a bit.