[mikekantor]

Originally Posted by LI89Max

I own an '89 Maxima. I had the engine changed with a used one (80k on it), at 400k, and the tranny changed @360k, with a brand new trans in the crate from Japan. the car will, at any time either totally drop the rpm's to 0 (at any speed), or have extreme hesitation/ or rough idle. I changed the fuel filter, injectors, pressure regulator, fuel rail, IAC assy, distributor assy, vacuum hoses, air filter, plugs, cap/rotor, and wires. I noticed that if i move the wiring harness the rough idle occurs. After moving the harness around a bit to make the rough idle occur, it dissapeared, as it often does, but now the tranny shift late from 1st to 2nd(the rpm's dont drop when it does shift, just goes into second, and rpm's keep climbing), but the 2nd to 3rd shift is a little harder. The shifting problem doesnt happen if the 1st gear rpm's stay under 3k. Anyone have any ideas? Anyone run into bad engine wiring harness's creating these problems? I have 430k on the car now, and wanted to at least hit 500k.

500K would be an awesome achievement. I wonder if some of your injector wiring is damaged, when you get a rough idle again, try unplugging injectors to see if any dont make a difference in idle, then go after that harness and follow it's wiring.

Have you unwrapped the engine harness to see if any wires are melted or stripped? Do you notice if it behaves worse on wet or high humidity days?