engine revs while stopped in drive

So if I'm at a red light and have my foot on the brake, sometimes the engine will rev up maybe 200 rpm.

It's enough to move the truck forward and I have to step on the brake harder.

I've cleaned the MAF sensor as well as the throttle body. I bought a new TB gasket but haven't installed it yet.

I've also replaced some hoses, but not all.

This weekend I'll install the gasket and I'm considering replacing all of the hoses.

I also have a high idle off a cold start when in park...around 1500rpm. Once I shift into a gear it'll drop back to normal.

Am I on the right track in trying to fix the problem? Or am I missing something?

 

Air conditioning and/or defrost running? I know in my 2nd gen when the AC compressor kicks in it'll bump up about that much and I need to brake a little harder to keep it stopped.

EDIT: I also have a higher idle when starting cold. If you let it run for 60 seconds or so does it gradually drop down? That's what mine does...of course again, mine is a 2nd gen with a 1GRFE. It's something to do with the computer keeping the revs a little higher to get the fluids warm faster I think.

 

Yep it definitely drops down gradually on the cold start. Maybe that's it.

I don't think it's the AC. Although I'd never thought of that so I haven't been looking for it.

I'll keep an eye out for that tomorrow when it's monsooning again and I'm keeping the fog down.

Thanks.

 

I had the same issue. I would go down a street at 25 mph. Let go of the gas to let it coast to a stop sign. And I notice the truck isn't slowing down and feels like the engine is revving to keep it at that speed. And it was very difficult to stop. I turned the truck off and turned it back on and it was fine after that.

 

The going up 200 rpm is the air conditioning. Once it does it again turn off your a/c and see if it drops back to normal an if it does that 200rpm spike is normal. Mine does it as well. The high idle is normal and should go away the warmer the engine gets.

 

Thanks for the replies.

It was the AC.