Surging At Idle

[Tommy R]

Hey y'all,

 

My new-to-me '99 K2500 Suburban has a bit of an idle surge. When stopped in Drive, it will occasionally surge with the revs fluctuating between 500-900 rpm. Sometimes it's strong enough to make me push the brake harder to keep it still. Other than being a bit down on power from what I expected (not a surprise) it's running just fine. I did some searching, but didn't see a specific tell-tale item that is typically to blame. Any suggestions?

 

FYI, I've not yet done a tune-up which I plan on. So if merely doing plugs/wires/cap/rotor/filters typically resolve this, that'd be great, but I'm expecting it to be a sensor. Oh, and it's a Vortec 350 with 119k miles.

 

Thanks!

Tommy

[Tommy R]

Anyone?

 

Thanks,

Tommy