I have a 2003 dodge ram 1500 4.7 recently I've had a high
idle issue, found out that the pvc on the back of the intake
was off and also broken. While parked my truck idles at
2000rpm. Ok I purchased the pvc and attached it back on
now my truck cranks but dies completely out unless I give it
gas. What could that be
Going on what you stated it is possible that the ISC unit is stuck closed, during you high idle the computer was trying to cut the idle back and it does that by closing the ISC so if it bottomed in some crud in the valve it could be stuck, I would recommend that you clean the throttle body and the ISC with throttle body cleaner and see if that get rid of your problem.
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