Heres the deal;
Car has a misfire that I can feel when in neutral/park. I cant distinguish it as much when it is under load.

When you listen to the exhaust by the tailpipe, you can hear the misfire about 1 time in 3 seconds when the car is cold.

When the car is hot (to the point where the fans kick in) you can hear it much more - maybe 3-4 times in 3 seconds. Its randomly misfiring. It will go misfire good good misfire misfire good misfire good good good misfire misfire good misfire. Etc etc. You get the idea.

Fuel injectors were cleaned/flowbenched etc in 2000 or so. The guy I bought it from was in the same car club thinger. He has drove it maybe 12,000km since then.

Tested fuel pressure:
Key on: 46psi held for long time
Engine running: 38 psi steady
Reving: PSI goes up accordingly

Injectors: All of them are at 16-17ohms resistance. The selenoid fires on them all.

Replaced: Cap/Rotor/Wires/Plugs/O2 sensor.

No Codes.

TPS works good.
IAC seems to work good.

IDeas?
The engine only has 85,000 miles on it (140,000 km).

Ignition module?

 

Try the ignition module.

 

How much do they run?
I Get Trade cost on parts at Napa and a few other places.

 

No idea, I've never bought an HEI module.