Engine revs up and down on cold starts

[Xris]

My brother and I both have this problem. I've got a 2000 GP SE with a 3100 and he's got a 97 Grand Am GT with a 3100.

When we start our engines the car will rev up and down repeatedly from 1k to 2k, maybe 10 times. After it warms up it stops and they run fine. What's the deal? Is this normal or something?

[geoffinbc]

Where do you live? Is it a moist cold climate? Are the stock intakes removed by any chance?

[Xris]

We live in TX, so it's usually pretty hot. I know he has an open cone intake. I have a fenderwell intake, but it started doing this before I installed it.

[A.Bejcek]

My '94 3100 does it too and it's driving me nuts! I wish I had a scanner because I have a feeling it's just a messed up sensor... a flakey TPS or CTS or something...

[stantmann]

You are leaking fuel at the injectors when the car is off. This about it, you are giving classic symptoms of a flooded engine. If you run into the store, and come back out 15 minutes later, does it happen then? I would think not, because it does not have time to flood the engine. If this is the case:
Take them out, clean them off and replace the o-rings. In a worst case scenario - replace the injectors.