Quiet Storm

I have a 1999 Suburban with a 454 engine. When I come to a stop the engine rpm will drop to about 525 and then surge to 700. It will continue to repeat this but not every time that I stop. Any ideas as to what would cause this.

I know its not a boat related question but some of you guy's know everything.

Scott72

Could be the TPS (throttle position sensor). Maybe you can get the codes read and see if anything comes up. Autozone used to do it for free, but not sure if they still will. Also, Suburban/Tahoe's are very sensitive to fuel filters. They should be changed every 3000 gallons of fuel.

Wally

iTrader: (1)

I agree with the two suggestions above....one other is to check the EGR valve....i had that happen to my dually once....it was carbon'd up. I took it appart and cleaned it and no more problems......oh and GM came out with a flash update about the EGR's where from what i was told they actually make the valve open/close twice as fast as before to "bounce" it off the seat and keep the carbon from building up. Not sure if its true or not cause i sold my dually but it may be worth checking into

tssteph

Just worked on a 98 suburban (454) with the exact same problem. Believe it or now the problem was with the plugs, the owner had went the extra mile and put some platinum tip plugs in it when he tuned it up. They were the culprit, the owne took them back the local AutoZone said it is not the first set that have been returned for similiar problems.

By the way, the EGR valve is very expensive so sit down if you choose to buy one.

Quiet Storm

Thanks for the suggestions. I'll start cheap and work up. I just had it tuned up about 5000 miles ago but I do work it hard.