I have a '97 Grand Cherokee with the 5.2L V-8. When the car sits for a while (more than 4 hours or so) it starts very hard. I have discovered that if I cycle the key from off to on and let the fuel pump run and do this a few times it starts right up.
My theory is that I lose fuel presser when it sits but from where...fuel pressure regulator? An injector... if so which one? How do I test for this without just starting to replace parts that may be perfectly good?
I am leaning towards it being a bad injector because sometimes when I start it it will run rought for a few seconds. I'm thinking that one cylinder is flooded from the injector leaking fuel into that cylinder. Again, how do I tell which injector it is without just randomly replacing injectors.