High RPM Rev at Startup

Necromancer · Post by **Necromancer** » 27 Jan 2008, 18:49

Whenever the car (1997 850 T-5, 115k) is cold and I start it, it revs up to about 2k and slowly backs down to around 800 RPM. It doesn't do this everytime but nearly 95% of the time.

I haven't had the car that long and it's always acted this way.
I'm worried about extra engine wear since its not primed with much oil at this point.

Post by **MadeInJapan** » 27 Jan 2008, 19:10

It's common and nothing to worry about.

Post by **sseir39** » 27 Jan 2008, 19:22

Working on a similar problem on son's 94 855T. Looked at the ISM or idle speed motor and it is messed up. Took some WD-40 and a little carb cleaner. Seemed to take care of the problem, but need to drive it a bit longer. These little motors do get gunked up.

Dick

Necromancer · Post by **Necromancer** » 28 Jan 2008, 17:29

Thanks guys, I may try the idle controller just for fun. I cleaned it up a little when I did the PCV system but I was afraid to spray to much cleaner at it. So that could be the problem.

Thanks again

Post by **Ozark Lee** » 28 Jan 2008, 17:56

The IAC valve is a great place to start. While not Volvo specific, we had a huge ice storm a few years ago which destroyed all of the squirrel nests in the trees. Since they had no nests they decided that the engine compartment on my '96 Suburban would be a great place to take refuge.

I had one heck of a surprise when I went out and started the car, it idled at about 2500 rpm and immediately threw a cel. I popped the hood and it was filled with every leaf in the neighborhood. In the process of nesting the yard rats ate through the wires to my IAC valve on the throttle body.

My insurance covered it on comprehensive and I got it back a few days later only to have them come back the next day and eat the whole danged harness. They also ate the harness on my other '91 Suburban since I was driving it while the other one was in the shop. That one I just fixed myself because I was tired of the State Farm claims people laughing at me. To this day the parts guy at Superior Chevrolet brings up the VIN and calls it the squirrel car.

...Lee

Post by **sseir39** » 28 Jan 2008, 18:38

I realize I am only one day out but no rev this morning.

Man, those GM wiring harness's must taste like nuts!

Dick

Post by **MadeInJapan** » 28 Jan 2008, 19:04

I'm protecting both my harness and my nuts!