well i had the same problem. It ended up being the pcm memory fuse in the fuse box under the hood. check the igition control module,crank shaft position sensor. that would be my first guess

95 s.e. 2.5l mtx ,koni yellows, h&r springs,kkm intake, ddm,custom catback exhaust, spec stage 3 , fidanza flywheel, all 98 svt midnight blue interior. , and much more....