2012 Malibu, 140k. Started about 1-2 months ago. It cranks but doesn’t start. The lights, radio, etc, come on just fine. I replaced the battery first off. The parts shop said the battery was borderline, it was due, so I replaced it. Still having it. Sometimes it starts and runs fine. Sometimes it cranks but doesn’t start. Sometimes it starts for a second but then dies. Sometimes it starts and rumbles and shakes like crazy, and then dies.
I’ve had the fuel pump relay changed twice. My shop is saying the fuel pump is testing ok. Earlier tonight, when it was cranking but not starting, I took out the fuel pump relay, did nothing to it, and put it back in 5 seconds later. It started right up.
Any ideas?
A failing crankshaft position sensor can cause the problem you describe.
Tester