Originally Posted by Whakeen

I understand you checked for leaks already but off the top of my head it sounds like a leak somewhere. Intake manifold gasket??

This could explain both issues. More oxygen exists in cold air so the leak is not large enough to lean the mixture out until thermal expansion creates a bigger area for air to come in.


Then when you shut off the motor the warm air inside has less oxygen and now a larger leak due to thermal expansion so it leans out the mixture and won't start.

You mentioned your buddy sprayed into the throttle bodies which then started the motor: you are making the mixture richer allowing ignition.

Or, this could be completely off...