Hello I just finished rebuilding the heads on my Pacifica it had a bad head gasket two burned intake valves and a bad intake manifold gasket. I went to turn the car on yesterday after triple checking everything was connected where it should be and the car wouldn't crank. I took apart the ignition cylinder assembly and found the plunger that actuates the ignition switch to be broken. I went to the dealer for a replacement part and they gave me the wrong vehicles ignition switch actuator so instead of spending more time going back to the dealer I decided to test starting the car with the key in the ignition cylinder turned to on and using a screw driver to turn ignition switch. The car started right up and instead of revving to an idle like any other car would start or like this Pacifica did before the head job it just conticontinuously revved in a pattern like follows... Vroom vroom..vroom vroom.. vroom vroom and would die. Or it would do two sets vroom vroom.. vroom vroom and die or once vroom vroom and die. one time it even went vroom vroom so many times before dying I lost countw. All the while it was blowing clouds of white smoke which was the left over coolant from the initial bad intake gasket where it literally poured out of the exhaust.my brother suggested replacing the oxygen sensors that I had not done so I did but it made no difference. Any help would be greatly appreciated.

 

The one system finally gave me a code p2074 I have unplugged the map sensor and tried starting it acted even worse less rdving more wanting to die than reset the computer and tried disconnecting the throttle position sensor and starting... No difference. Not sure if this is an accurate way of testing these possible culprits but I know you they weren't acting like this before the rebuild. I found this video of someone's pt cruiser whose idle is revving almost identical to mine just I don't have a funny knock in the back round.

 

I just changed the MAP sensor and TPS sensor but nothing still revving instead of idling. The white cloud smoke has reduced to almost nothing so the old coolant is almost al gone. I read on a different site that this code also means large vacuum leak I've. I've checked all hoses and cables, I marked them before dissambly so I would be able to reconnect everything faster

 

RESOLVED : I had not put the egr tube to the upper intake manifold seal back in. When i disassembled everything initially a rubber seal fell on the ground and i wasn't able to see where it came from it caught my attention only after hitting the floor. so that mystery seal was my problem ...