My mom's 01' tahoe is bone stock.
The problem is it won't idle right, the needle bounces from 300-400 rpm's and often dies out. But once you take off it drives fine. What is the problem and how can I fix it?

Thanks,
Nick

 

try cleaning the TB, how many miles does it have?

 

Check the idle air control valve to make sure it's not sticking. If it's higher mileage, get yourself a good throttle body / carb cleaner and give the throttle body a good cleaning.

 

Only 56K. Mom driven, bone stock.

 

She is thinking of trading it in because of this small problem. So I want to find out what is wrong and get it fixed, ASAP.

 

Can you get it to hold steady if you crack the throttle just a little bit? If so, I'd say it's the IAC valve. I think they are like $80 at the dealer, easy to put on.

 

In park if I give it a little gas and let off it will do the same thing.
I have to hold the throttle steady and not let off.

 

I had that problem too...does it get any better as it warms up? In my case, the wires for the throttle body were routed around the EGR return pipe because of the Radix, the wires melted to the pipe and shorted out, causing my IAC to malfunction. I could drive it fine, but it would die on me if I let the throttle blade close all the way. Try setting the IAC manually and leaving it unplugged. Play around with it a little, change it, reinstall, start the truck and see if you can get it to idle properly. It will light the SES light until you plug it back in and drive a little bit, or the dealer can reset the code for free, if they're nice. If that fixes your problem, get a new IAC valve or check the wiring to make sure there are no shorts.

 

thanks, will do. Should I check the trottle body first. Because she dosen't have a radix, her car is stock.

 

I'd try cleaning the throttle body as a starting point, if it's gummed up with carbon, it may not be allowing the IAC to function properly.