99 GT Missing Out...

Kane

Founding Member
Mar 22, 1999
489
0
17
Indianapolis, IN USA
I know this topic has been beat to death, and I've been using the search feature for hours, but I'll post this anyway.

I've got a 99 35th Anniv GT with about 60K miles. Just recently I've noticed a slight miss under acceleration. When the car is first started, it seems to run pretty good. After driving it for awhile, the miss appears and starts to get worse. When I parked it in the garage tonight and listened as I gave it some gas, the rev sounded rough. I've had one coil pack replaced in the past, and it sounded similar to this...but there is no check engine light. I waited awhile, then I went back into the garage and the car sounds normal.

I read somewhere that bad spark plugs perform worse when they get hot...maybe this is the reason for the miss getting worse as I drive it longer.

This is what I think I'll do:

-Clean MAF
-Replace fuel filter
-Replace plugs
-Reset PCM

I've been cleaning my IAC for awhile and sticking it back on. I'll be replacing it soon. Could this also be causing a miss?

BTW, what plugs do you recomment? Autolite 764s? Motorcraft AGSF-32C? What?