Originally Posted by wolfman01
Instead of throwing random parts at the car, I would get values for the operational ranges of the sensors, and hook up an OBD computer to the car if one can, that shows live data as it's being driven. Once the car starts to act up, look at which sensor is going offline. I would start running the wiring loom beginning where that sensor is installed. A 20 year old car with 60k miles on it has very likely been the subject of curiosity by rodents at some point in it's extended period of sitting around. Barring that, look for corroded grounds. Intermittent issues like this are typically not caused by a part failure.
If no OBD, then you have to use a good volt/ohm meter and look at the values the hard way.
I don't have access to something like an OBD computer, although that would be nice. On the other hand, my dad has a volt meter he uses for working on pumps for people's houses. I don't know much at all about mechanics or electrical issues, so what/how do you mean looking at values the hard way?