Chevrolet Repair Questions? Ask a Mechanic for Answers ASAP
If the engine starts with the cam sensor unplugged it usually indicates that it has jumped time. Has any work been performed recently?
Check the resistance of the Intake Camshaft Position (CMP) actuator solenoid. Resistance should be between 5-9 ohms at room temperature. Note: Compare the resistance to exhaust solenoid next to it, should be the same.
Any trouble codes?
I have to step away for a few minutes, do you want me to opt out and let someone else pick it up or are you ok to wait?
The p0507 is a throttle position sensor code. It shouldn't affect the starting by unplugging the cam sensor if the throttle is at fault.
Have you checked the resistance of the CMPs?
So you replaced them in an attempt to fix the problem or you replaced them because they tested faulty?
If you start and run the engine with the cam sensor unplugged will it set a cam sensor code?
Have you tried replacing the cam position sensor? If it is the only apparent thing causing it to not start you should probably replace it to eliminate it as a possible cause.
I'm convinced that the timing is off. That's the only way it would affect the engine starting by unplugging the cam position sensor.
Would you like to save a little time on back and forth by listing the things that you have already replaced and tested?
It might make diagnosis a little easier.