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Why would My 03 Hummer sometimes cranks over but doesn’t start?


Topic starter

03 Hummer H2, 130k miles, No codes. 

It only started doing this after a cheap set of injectors were installed. Since then I have changed to high quality injectors, coils, plugs, wires, fuel relay, fuel filter, fuel pump, fuel pressure regulator, camshaft positioning sensor, engine coolant temp sensor. 

I was going to change the crankshaft position sensor next. But would like your opinion.

2 Answers

Before throwing a Crankshaft Position Sensor at it why not hook up a cheap scanner and see if it has an RPM reading during the Crank/No Start?

If it's showing rpms while cranking then the reason for the No Start isn't the crank sensor

Posted by: @rockfrd1

But would like your opinion.

Have you checked our FAQ?

Yes I have. This is why I’m asking for further advice

Have you pressure tested the engine, fuel ... or you are changing parts without actually checking? Have you checked you had done all that work correctly?

I have done a pressure test. It was low. So I had a new fuel pump and fuel filter installed