I have a TPI with an OBD1 computer. The system was working perfectly before I put my new motor in. After installing the motor I went through two heat cycles like the builder suggested and then changed the oil and drove it into town for a test. It ran good as long as I kept my foot out of it. If I tried to get on it hard, it would pop and sputter like it was out of time or something. After I got it home the check engine light came on and was giving me both high and low voltage @ the TPS. I got a new TPS and no change. I got another computer and no change except now it only says high voltage. When I put a meter on the signal wire coming out of the TPS with the key on it reads the same as the voltage going in--4.86VDC. I can take the TPS clear out of the picture and still get the same reading on the wires on the back of the computer. I have no continuity through the wires in the harness from supply to signal so I know the harness hasn't got a short. I can take the computer out of the car and when I check for continuity between the pin supplying the power to the TPS and the pin for the return signal. I get a momentary reading and then open circuit? If I had any hair I would be pulling it out right now!! Two TPS sensors and two computers and the same results? I'm lost. I could understand if the harness had a short, but it doesn't. :sos: Art