rough idle of 2000 3500

I have a 2000 GMC 3500, when it is in drive and i am sitting at a light it idles rough and the rpms go up and down. I have an appt. at the dealer on wednesday, I was just wondering what this is from and can I fix it myself? thanks<p>joe

 

Im not an expert on cars but try changing the gas brand that you use and use the highest octane mobil along with a really good fuel additive. See if it does the trick. There is a brand called bradahl or sounds like that . I just put some in last night and it took out the pinging but yours is a new truck so im just guessing it might be it.<p><br>Always use high octane gas from a mobil staion your motors run better and dont use the gas from cheap stations like speedy or total.

 

Is it a gas or diesel?<br>If its a diesel, then it could be a variety of things from algea in the tank and lines, to a bad filter, or injector pump, and fuel solenoid driver.<br>Dino<p>----------<br> Professional Ice and Snow Management <br>Products:Services:Equipment www.sima.org

 

the truck has a warranty so there is no point in messing with it yourself!

 

No magic in octane, and no point in buying more than your engine requires. I'd bet on an intermittent vacuum leak.

[Edited by Alan on 08-04-2000 at 10:59 PM]