My dad has a 1987 2.5 944s. The problem he has got appears to be an ignition related fault and I wondered if anyone out there can help. The problem started as an intermittent misfire, which would clear itself. My father decided to change the spark plug leads, thinking this was the fault. It ran for a while with the misfire, getting gradually worse. He now seems to have a car that will no longer run. The RAC man told him that the timing belt had jumped a tooth, not convinced that would cause intermittent misfire then drop to 3 cylinders and eventual no running. Can anyone tell me where the TDC and crank speed sensors are located as I think one of these may be causing a problem. We have changed the DME, he has a spare TDC sensor, a spare airflow meter, a spare ignition module, so we are covering bases. Finally, could the cam drive chain jumping teeth cause any of these symptoms?

 

Does the dead cylinder's plug have oil on it?

 

None of the cylinders have oil on the plugs. There now does not appear to be any one cylinder causing the problem, none of them are working now!!. There is also no mayonnaise in the oil or oil in the water, so gasket looks ok.