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Juan Crespo
Juan Crespo, Tech Trainer
Category: Car
Satisfied Customers: 1526
Experience:  A.S.E. Master Technician, Advanced Level, Emissions - Asian, Domestic, & European
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Porsche 944: I have an 1982, 944 it has been running fine but

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I have an 1982, 944 it has been running fine but overnight unexpectedly, it now will not start. I have replaced the coil, there is fuel, ignition but no starting of the engine. An auto electrician cannot find any fault but suspects that it may be a sensor somewhere that is prohibiting start up. Can you suggest a probable cause.

Welcome! The Engine Control Unit (ECU) uses signals from the Reference Mark Sensor and the Speed Sensor to control ignition and injection. One or both of these sensors might be faulty causing the no start issue. These sensors are best tested with an oscilloscope, although a Fresnel lens front L.E.D. can also be used to detect basic signals.

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