Chevrolet Repair Questions? Ask a Chevy Mechanic for Answers ASAP
Hi there, I am Cam. Your injector resistance, do you mean across the injector wiring from the ECM you are getting 28 ohms?
OK, are you able to see if you get a pulse with a noid light on each:
OK, I see you have many new ignition wires and such, but did you check for spark on that one?
No IO don't think it will be causing this although we cannot rule out the ECM yet. Can you do a fuel injector flow test?
So that means its not injectors, if you get spark and its the same and in proper time then we are looking at base engine. You did a compression test, but did you verify exhaust valve is opening? If its stuck closed it will still have great compression.
That is likely just due to the hard misfire on #4.
It might be. Can you remove the vacuum lines to the crankcase, plug the ports then spray some carb cleaner or such in the oil filler and see if you get a reaction from the engine. If you do then it does confirm they are leaking internally.
Is there a plugged catalytic converter?
Ok, lets check that intake and see next.
For this it would be back pressure as measured from the pre converter sensor. Anything over 1 psi at any time is the limit.
Let me get one. NO bulletins.
Which engine, 3.5 or 3.9?
Here is the diagnose for P0300.