Last week it snowed and my car had been sitting for a few days and when I finnally started it, it drove for about 5 miles before the tachometer gave a reading. This happened again this week when it snowed a little and the car had been sitting for a day or 2. I've had this problem before, I've never really figured it out. Also sometimes I will be cruising and the engine will go a berserk, rpms will jump up and down repeatedly and the engine will cut on and off. Sometimes cuts off for good. I've changed ECU's 2 times in the last year and now I have a reman, the problem just keeps comming back. Whatever the problem is, it is killing my ECU's i believe. Also the car misfires/hesitates noticibly ONLY under 4000 RPMS, more noticible when the car is not yet warmed up. I think all of these problems are tied together somehow. This has been a nightmare, ANY INFO/HELP/SUGGESTIONS, are greatly appreciated.

any CEL's? and if your car is bucking and lunging, it may be a spark issue. how long ago was it since you replaced your plugs, wires, and coil? as far as your tach messing around..maybe a bad connection, grounds out somewhere...i dunno.

Sounds like you have a short in the harness.

I had the same problem after installing the safc, the problem was loose conections. So if you haven't soldered or crimped anything to your ecu harness just go with what ^^^ said, shorted harness.

That might also explain frying ECU's.

Yeah... Its been doing it for over a year now, on and off. So only chance of finding it would be to start at the ecu and trace all the wires until I find the short?

I give up, I'm selling this POS.