I have a 2007 22i. 350 vortex 5.7l engine. When I turn the key on I hear the starter trying to engage then it dis-engages sounds like knock knock knock as the starter tries to engage the flywheel and start the engine but never stays engaged to start the engine. When I jump the posts on the starter it engages and starts the engine. After I run it for a bit I can turn it off and it will start for a while but eventually I get back to the same thing. What I have done for troubleshooting is tried replacing relays, replaced starter, cleaned all battery terminals, replaced ignition switch, found no blown fuses. I'm at a loss why I can jump terminals to start but it won't from the ignition switch. I also have checked output of positive output to started and it gets constant 12 volts as well as the ignition wire. Any help would be appreciated.
thanks
Stu
thanks
Stu