Need Help!!!

[niki_trinity]

I have a 1999 grand am 3.4. I recently had the engine replaced with a 2002 engine of the same make. When I first got the car back the idle was too low, the engine loped and and the lights would dim on and off when the brake was pushed. The car would also jerk when you held the brake or put the car in park. I took the car to someone else who replaced the intake ,EGR, spark plugs and wires. Now the car is idled too high and will acccelerate on its own. When the car was hooked up to a computer it didn't show any bad codes and I nor they know what is wrong. Anyone else have a similar problem and what was wrong? Thanks in advance.

[GTP Dad]

Check the car for a vacuum leak. High idle usually indicates that there is air leaking into the engine from another source than the throttle body. Something as simple as a disconnected line can cause this problem.

[crazy Jim]

there is a big vacuume line between the engine and the firewall that is kinda difficult to see, you will want to check it out..

[niki_trinity]

all the hoses are connected and there isn't a hissing noise or anything.( I'm to my breaking point with this car full coverage insurance and a ditch come to mind.lol.)

[xeroinfinity]

I'd check your idle air control(IAC) this effects and controls idle. Alot of times the area where the sensor is located gets carbon build up and begins to mess with idle.

We have some R&R procedures in the Tips and Maintenance subforum at the top of the grand am forums.

Also since you swapped engines make sure all of the plug-in connectors on the engine are making good contact. Sometimes you can get dirty/greasy stuff in them and it could cause some problems.

Good Luck

[niki_trinity]

thanks, I've noticed that the car doesn't vibrate as much when the air is on and held its speed on cruise control. without it on I noticed that it still increases speed with the cruise control. I'm really hoping that this is going to be a cheap fix. I've already put my arm and leg into it.