remlle

let me start off by saying hi and I just purchased my first stang. Ive always been a sideline fan and love the stangs. what I got was a 89 mustang GT vert Automatic all original. while driving it home one day (100miles after I bought it) transmission started to slip. wouldn't go into 3rd or 4th. so I took it into a ship they rebuilt it and said it was really bad inside. 1600 bucks for a rebuild and a stage2 transgo shift kit.got the car back and It was idling rough so I changed the plugs, wires, rotor, and cap. also changed antifreeze, oil, filter, fuel filter, and cleaned it out. still has a bit of a rough idle. when Im driving it I don't seem to feel any sluggishness or hesitation when I get on it but when I get to a cruising speed the thing wants to jerk or lunge forward. any ideas? its just bad enough it feels like bumps but does it on every road. and its definatly the engine cuz the exhaust changes tones when its doing it. I checked for milky oil and it seems fine. one plug (back plug on passenger side of engine) was very crusted with white hard material. flakes off but that was the old plugs. haven't checked since I changed them to see if its come back. any ideas would be awesome.

Well after spending the day messing with it. I found it. something so stupid I cant believe it.
the guy at the auto part store told me the plugs were gapped already. HAHAHAH not even close. all 8 were different gaps.
gaped the motocraft platinums to .044 and its a world of difference.