Any suggestions on this one, car came in with misfire, code read gave P0304 misfire no 4 cyl. Erase codes and misfire goes and mil light stays out. Periodically vehicle will then start to misfire again with same fault codes, erase codes and it will run ok for anything up to 2 weeks. Has had 4 plugs, new coil pack, checked for air leaks and checked egr operation, swapped injectors around to try to move misfire but to no avail. Compression test gave approx 200 psi across the board whether hot or cold.
Read in the archives that the 1.8 zafira suffered with ecu failure not firing a coil but the 1.6 runs on a multec system and not simtec. Does anybody know if our system has had similar problems?
The problem that we have is that you can turn the car off and restart it and the misfire will go. We then cannot recreate the fault until the customer rings up ranting and raving and yes he does not want to spend a lot of money on the car!