97 camaro: wacky gauge behavior!

my girlfriend was telling me her car has been acting weird. i have not got to test drive the car yet and try to diagnose the problems but here is how she described it to me...
some times it idles fast, then slow, then fast, ect and the heat guage and the oil pump guage fluctuates from low to high periodically.

first i thought maybe she needed a new IAC (i think that's the abbreviations) cause i've heard of that being a problem on a few LT1's, but i know nothing about these 3800 motors.
what do you guys think?
thanks,
michael

ps. i know she needs a new battery, could this just be screwing up the current to the guages causing them to act up?

my gauges were acting up, and it was due to a bad engine to body ground. check the ground cable that goes from the firewall to the engine.

You sure she needs a new battery and not a new alternator? With the alternator going bad, it can cause the gages to do funny things.

Originally posted by hawgs
You sure she needs a new battery and not a new alternator? With the alternator going bad, it can cause the gages to do funny things.
well that is very possible. i never did get her down to autozone to have them check to see whether it was the battery or the alternator....maybe that blew her foglights too if the voltage was surging. maybe she'll go to autozone now!!!
but what about the varying idle? i don't think the alternator would do that, would it?

It could be... I'd try testing the alternator and see how that turns out and if it is bad replacing it. It could very well not be sending out enough voltage to everything and causing a surge in the idle.