HELLO. I need some guidance/help. I have rebuilt my 2003 4.0 L grand cherokee with a new cylinder head, new stock intake manifold, new timing chain, new spark plugs, new spark plug coil rail, new water pump, new thermostat, and new hoses. When I went to start up, had very high idle. (3000-4000 rpm). connected all vacuum hoses, fixed/repaired all the vacuum leaks and engine still idled high. At start up engine ran at 2000 rpm, and once warmed up it ran at (3000-4000 rpm). Once engine was warm, it would not crank over in Park. Put in neutral and motor cranked and started. I took off the throttle body and cleaned it as good as I could, I installed a new idle air controller and a new throttle position sensor. Went for a ride and kept the speed at 55 mph for 15-20 minutes in an effort to reprogram the engine but still have high idle (3000 to 4000 rpm). Engine ran great when running at 55 mph (except for the high idle and having to stand on the brakes in order to stop). I am thinking about changing the MAP sensor, but I don't know if that will work or not. Does anyone have any suggestions or can point me in the correct direction? The jeep did not do this before I rebuilt it. I am totally stumped at this point and will appreciate any responses.

Thank you.