I'm getting little overwhelmed with this car. I replaced everything engine related, sensors, coils, CAS, TPS, AFM, etc. including the emission harness from a know good running car, no improvement.

88 SE. manual windows/mirrors, but P/S and A/C, high impedance harness stock, no modifications, engine is fresh, 105 psi compression, good fuel pressure, good injectors, no vaccum leaks.

most of the time she runs good. when the problem is not pressend, she runs really strong, like a normal rx7.

if I do a lot of driving, running errands etc. eventually it will start missfiring, maybe after 2-3 hours of driving, sometimes sooner, but never right away. sometimes it goes away sometimes it does not.

when the problem is pressent, I'm getting intermittent spark on LEADING.

occasionally the intermittent problem is happening on TRAILING, then the engine barely runs, its almost impossible to drive and it dies and it is very hard to start, the plugs are soaked..

typically, it is happening on Leading only. the signal to the plug is random, when i rev the engine the signal is gone, then it comes back at the idle. when its missing, the leading is hitting at least 90 deg away from the mark, because I cant see it.

I never experienced similar problem..

Any ideas?

 

I chased a strange issue like this a while ago. All I did was literally replace my plugs and I was good to go. No real explanation, but after weeks of troubleshooting and parts swapping, it did the trick.