1995 Volvo 940 flywheel

1995 940 has a crank position sensor mounted at the top rear of the engine which reads cranks position off the flywheel. Though not adjustable, it is a part which fails often causing weird and intermittent no start/hard start problems as well as other faults. While the part is not too expensive, you do have to crawl on top of the engine to see it, and its a pain to replace. Guess you could remove the hood, but I have changed mine without doing so. Get light on the area,and you can do it. If you are having timing too far advanced issues (running on when killing engine or "pinging" on acceleration several other parts may be suspect. Knock sensor, spark plug issues, carbon buildup, O2 sensor, lean condition and more. Good luck.