What are some symptoms of a bad Tps on a 5.8? My 95 runs almost perfect it has a smooth idle but shakes at times. Hooked a jumper wire to the OBD I port and it did a self test and it started running a little Rough. My buddy also revved it up to like 3,000 and said it rocks a lot. The motor mounts and trans mount are new and so are the plugs wires cap and rotor. The coil has not been changed. Also the check engine light comes on as soon as you start driving even after unhooking the battery. I'm going to get a code reader for OBD I because I'm not too great at counting the flashes and typing the number down..