98 Malibu - sticking throttle..?..

[BoxMN]

Another Malibu question 98, 3.1 liter, 130k miles, has been running great.

Last week, I had it happen once after freeway driving (using cruise) and getting off ramp, it felt like it was braking worse... well, it wasn't the brakes, it ended up that the engine was stuck wanting to run about 2800 rpm. I pulled into a lot, though, oh carp... and turned it off. Started it up again, and all was well.

This weekend my son was using it, and the same thing happened twice on his way to Hudson and Blaine. Only happened after long freeway stints (not sure if he was using cruise...) and after he shut it off, and started it again, it ran fine.

No check engine lights came on. Any ideas? I am going to bring it in as soon as I can get it in, can't have my wife driving it like that, and don't want to cause accident or break things. Thanks for any advice!

[Macgyver55]

Since it is intermittent, my first thought would be a sticking IAC valve, or possibly a binding throttle plate from carbon build up or maybe even a sticking cruise control cable.

The check engine light may not come on since you keep shutting it off quickly to reset it. If it were left to keep idling fast it most likely would set a p0507.

[Jeremy airjer W]

Agreed.

A good throttle body cleaning can't hurt.

next time it happens pop the hood and see if the throttle is closed. If it is than the IAC is probably stuck.

[BoxMN]

Thanks guys! Will see if it happens and check, or have my local shop buddy help me. He also usually tells me the stuff I can do myself, so that is cool!

[BoxMN]

UPDATE

So there was a code (don't have paperwork here) but they cleaned the IAC and the throttle body, cleared the code, and tested and I am good to go. Just $90 for labor. You guys were spot on. Thanks! Now just gotta get wife back into the "death trap" and out of the truck, haha!

[Jeremy airjer W]