Fault
Caller reported to the helpline that the vehicle had developed a misfire under load, especially when the engine was hot. It was also mentioned that as the misfire occurred, the engine would suddenly appear to run on only 3 cylinders. The engine running on 3 cylinders would continue until the ignition was switched OFF. If the engine was re-started the engine would run on all 4 cylinders again until the misfire reoccurred under load, and then the engine once again appeared to be running on only 3 cylinders.
Cause
The initial misfire fault under load was finally traced to cylinder no 1 on the engine. The fault was caused by a poor output from the DIS ignition coil pack fitted to the vehicle. Upon testing the vehicle, it was discovered that when the misfire occurred on cylinder no 1, the Multec engine management ECM would switch OFF the fuel injector for the affected cylinder. The caller reported that when the engine was switched OFF and then restarted the misfire would disappear, and the fuel injector for cylinder no 1 would operate normally again download
