IAT reading 25 degrees higher than ECT

[BMWMD82]

Hey guys,
Like the title says, I have noticed my IAT reads quite a bit higher than coolant temp with the engine totally cold. Today I did some logging and ECT was 67 degrees, while IAT was 93 or so. The temperature in my garage was right around 67, so IAT is reading too high.

What gives? This is an LS7 with an E38 using stock Corvette/Camaro IAT calibration tables. MAF sensor is a new, stock GM part. I do not have the engine running yet, but this does not seem right. Bad MAF?

Andy's LS7 speartech file.hpt

[blindsquirrel]

A new, stock GM MAF that fits the same application as what the tune file is from?

The IAT table is in resistance vs temp, you can measure the resistance with a DVOM and compare to the actual ambient to see if it matches.

[BMWMD82]

I believe it is a brand new GM replacement MAF. It was supplied by Speartech, along with my engine harness and ECU.

I did some more testing, and found the temperature creeps up with the key switched on without the engine running. Maybe this is normal from the MAF heating up? It was not ideal, but I set up my shop fan to blow some air through the intake pipe, and the temperature dropped to within 5 degrees of coolant temperature. Next, I will remove the MAF and blow air directly on it for testing.

So this may be a non issue. I will do some more testing.

[blindsquirrel]

I always find it funny the trouble people go thru with stinkin' MAFs, when most of the time they run better in plain SD and the fancy MAF (and all the finicky crap required to make them work right) tossed in the spare parts drawer.