I have a 1996 GT and it's running extremely rough. When driving, my AFR is all over the place. It can sometimes be as low as 10:1 then as high as 19:1. I can occasionally hear backfiring while climbing to 3k-4k. Idle isn't smooth either, it'll almost look like a misfire but then smooth itself out. I pulled out a few of my brand new spark plugs and they were covered in carbon.
When I hook up my scanner my LTFT B1 is +25%, and LTFT B2 is -16%. My STFTs both are all over the place while driving, sometimes they'll hit 0% at idle but it's rare. Everything else looked normal, no codes set. I just replaced intake manifold gaskets and couldn't find any vacuum leaks. I'm pulling my hair out trying to figure this out, so any help is appreciated.
Engine mods : PI Headswap, Comp Cam XE262AH, 24 lb/hr fuel injectors, Edelbrock Victor Jr intake manifold & fuel rails, BBK 75mm TB & Plenum, BBK Longtube headers, Evil Energy Adjustable FPR
When I hook up my scanner my LTFT B1 is +25%, and LTFT B2 is -16%. My STFTs both are all over the place while driving, sometimes they'll hit 0% at idle but it's rare. Everything else looked normal, no codes set. I just replaced intake manifold gaskets and couldn't find any vacuum leaks. I'm pulling my hair out trying to figure this out, so any help is appreciated.
Engine mods : PI Headswap, Comp Cam XE262AH, 24 lb/hr fuel injectors, Edelbrock Victor Jr intake manifold & fuel rails, BBK 75mm TB & Plenum, BBK Longtube headers, Evil Energy Adjustable FPR