94 Skylark 3.1 high idle on cold start

[majic723]

I just recently purchased this vehicle, a 1994 Buick Skylark 3.1. When first started in morning or after sitting a long time it has an extremely high idle which seems to lower down to normal after warming up. When i put the car in gear while the idle is high the tranny slams into gear, i assume because it is idling so high. Also after driving for 30 minutes or so and i shut it off, if i go to start it again before it cools down it dies when put in gear. I have replaced the TPS which made no difference at all. Just wondering if anybody has any advice before i start throwing different parts on, such as an Idle Air Control Valve. Thanks

[Tom_SF]

It could be the EGR valve or the MAP sensor. They're both easy to replace. You might also change the charcoal canister (under the washer fluid tank) which is also easy to replace but a lot of people tend to overlook it when it's time to get a new one.

But then it could be the ignition coil?

[maxwedge]

Welcome to AF. I don't think we want to randomly replace parts here. A full scan may reveal a tired or dirty IAC, or bad a coolant temp sensor. Also clean the throttle body.