m3out

Hi Moses, I'm having an annoying ignition problem with my 89 Wrangler 2.5 TBI. It wil start without any problems, but after a few minutes (sometimes after a day of good driving) the engine backfires and the tachometer jumps up and down at the same time. The engine dies, but from time to time keeps firing in the distributor (with ignition switch still in on position). I changed the CPS and the ignition module, but the problem remains. I've read your tuning and troubleshooting page, but still can't figure out how to isolate this problem. The only thing I can think of is the ECU, or a short in the wiring going to the ICM. All wiring looks good (very good even). Is there a way to find out if the problem is in the ECU, without first buying a new one? Kind regards, Martijn.