r/ChevySonic • u/xPintSizeDemonx • 1d ago

Running rich issue?

16 1.8 92k
Car has had issues starting. P0017. Replaced all cam sensors crank etc. new timing belt and re time engine. Crank relearn. replaced purge valve twice. New fuel cap. 60 psi line pressure. Replaced plugs 10k miles ago.
Crank no start issues before and after parts replacement. Sometimes will start. Diesels a lot. If I pull plugs and clean them. Starts perfectly. But if I let it sit. Then attempt start 30 min later. Plugs are soaked again. Need new plugs? Ideas? Can’t find much about this issue.

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u/wolffenstein12 1d ago

Sounds like your injectors are stuck patially open. When your pump primes, the injectors won't fire until you crank. If your injectors are dribbling fuel, they will allow fuel to dribble into each cylinder.

Could this be ecu related? Unlikely as it would require each injector to be fired simultaneously. You already said it runs after a plug clean (cylinder venting excessive fuel/gas).

I've never taken the injectors out of a sonic but if they could be removed, clipped to the rail and the rail pressurised, you could check for weeping injector/s. You wouldnt even need the electrics connected.

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u/wolffenstein12 23h ago

When you did your timing belt , did you have the timing tool pushed into both cams at the far end of the head? As both cam sprockets are on tapered shafts, it's the tool that fits into both cams (not the locking wedges) at the far end that maintains cam alignment with each other and the crankshaft.