MAT is Manifold Air Temperature (or IAT). If it was reading 4-6v the air temp would be alot higher than 40* C. Column AA shows the MAT as an actual temperature. Column X shows what the MAF is reading in Grams Per Second.

*I assume Freescan reads in Centegrade (based on a water temp of 90*) the way Datamaster does. If it is actually reading in Farenheight then that could be the problem. I can double check tonight though.

 

Update

Ive gone back and readjusted all the rockers to right at 0 lash and reinstalled my stock opti spark and all is well.Engine revs fine with no misfiring at all.

Next thing to do it try and get with msd and find out what I need to do with this distributor.

Thanks for all the help guys.

 

I am glad you finally found the culprit.

Hopefully they can fix the prob with the dist or get you a refund for it.

Lloyd