Q: run away idle/engine speed

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When I start the van it idles fine until I put it in reverse or drive, and then when I return to park or neutral the idle is very high. I can shut the van off and restart it and it's fine until I put it in gear again. It also accelerates on it's own when driving, like the cruise is on. Turn key off/On back to normal for 30 sec.

A/C on also has same like effect.

Replaced TPS and ICM.

My car has 60000 miles.
My car has an automatic transmission.

This can be cause by a few things. A sticking throttle cable or throttle body, due to excess carbon buildup, or expansion from heating, idle air control valve issue, it can also be caused by a faulty temperature sensor signal to the ECM. I suggest having a certified technician, like one from YourMechanic, diagnose your idling issue to determine the exact cause of your concern.

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