Hello, I've been trying to get my neon to idle normally. The car is a five speed and is up on jack stands without the half-shafts installed. When I started it the first few times it would just rev up to three grand and stay there. In the end if I unplug the speed sensor it starts and idles normally ( I noticed the speedo was at around ten MPH in neutral.) My question is was the speed sensor the culprit? The DTC was P0108 MAP output voltage too high. I could hear the IAC opening all the way by the sound of the air going through increasing. The engine is out of an '03 ('96 head) that I laser cut the crank trigger for and the car is a '95. Thanks for any help I may receive.

 

once you get it back on the ground see how it does. it might be idling high because there's no real friction for the transmission to overcome.

 

Just to update. The car idles good and runs fine. Thanks Dodge forum.