Hi Guys,

Running an 87 MAF setup ( $32B ).

Presently tuning the BIN.

The part throttle response was fine until to weather turned 20 degrees warmer.

The car has no tip-in power at all. No change in the BIN tuning.

The only difference in the data logs is the MAT went from 95 degrees F on a cooler day ( 70 degrees F ) to 131 degrees F on a warm day ( 87 degrees F).

How does the MAT parameter effect the overall engine control?

I thought the MAF handled temperature effects?

Ideal Gas Law : PV = nRT

Help is appreciated!

Best Regards,

Bruce

 

In the $32B MAF bins, the MAT has no effect on the control. It is only used as an enabling parameter for EGR.

The MATs used in these cars are also very slow to respond, so they're not the best indicator of charge air temperature. They're really just coolant temp sensors.

Your MAF may not be doing a good job compensating for the air temperature difference which good be skewing the tune.

For example, Micro-Tech MAFs have a tendency run rich when cold and lean when warm. Your MAF may be doing something similar (you should be able to see this in the BLMs), or it could just be intake heat soak resulting in reduced performance, due to the reduced charge density.

What are the coolant temps,T-stat and fan on/off settings? They may be a factor.