Thread: High idle

When this happens, it's normally after i've driven on the freeway. Coming to a stop (about 5mph-10mph) I throw it into neutral and then the rpms stay at about 1400-1500. I too took off my IACV and AAC valve to clean. Both weren't very dirty. When I fist started this thread, I did a check for trouble codes. Only code I got was P0455 or P0433. I forgot which one it was. Yesterday it did it again, but this time no code. I've had this car for almost 4 years now, I haven't even messed with the idle screw.

I just hope this doesn't affect my emissions test in July. Other than this sometimes idle problem, the car runs great. No ses light either.
One question about the AAC valve. When I took it apart to clean, I spun the little shaft. Is this suppose to be set a certain way? Does it matter if it's all the way clockwise or counter clockwise? In between?

You need to reset your base idle and double check your iacv resolution, make sure the base idle is within specs and make sure your iacv valve is actually at the correct threshold in order to open and close properly. It could also be getting stuck, hence why you get the random high idle issue.

I would clean the iacv(smother it with brake cleaner), try and get access to a consult cable + laptop, redo the base idle (do timing while you are at it as well) and make sure the iacv valve is within specs. Remember, playing with the idle screw while in timing mode will set your base idle, with it not in timing mode will set your IACV valve/idle RPM.

Goodluck

It's still doing it. It always happens after it's been warmed up, been driven awhile. Comes and goes. Another weird thing is, my car almost stalled once yesterday. When it happened I was at a stop light, and the rpm just dipped really low, then back to normal. So how do I adjust the idle? I read somewhere that I had to unplug the tps sensor, is this right? I took the IACV valve off and cleaned it. It wasn't dirty really, just a little black.

If the valve is bad, shouldn't I just replace it ? I'm thinking about picking up a new one at autozone. I don't think messing with the idle screw is going to help me much. Just now I went to the store to pick up a money order. First time I drove the car since yesterday.

I get back to my driveway and it's idling fine, but then a minute later the rpm starts to creep up high. I think this thing is done. How often do these things go bad? As far as I know this is the original IAC valve. 1998 200SX SE-R 133,940 miles.

Found an oil leak this morning. Looks like it's coming from the distributor or underneath it. Or maybe it's from the hose that goes to that little black metal thing that sits in front of the valve cover. Would a leak in this area cause my high idle? PCV hose has a crack in it too, right at the end. I don't think that's the problem though.

My brother borrowed my car yesterday. When I started my car up to go to his house the idle was pretty high. It stayed at 1600 for awhile. So I unplugged the tps sensor, idle when back to normal. He drove the car over a hundred miles and not once did the car idle funny.
This car man, I don't know. Maybe it was the seafoam I put into the gas tank a month ago? Right after I used seafoam, that idle shit started happening.

Clean the iac with some cleaner spray, had the same problem. Clean your air temp sensor, and your MAF could cause it as well.

I cleaned the IAC like 3 times already. Air temp sensor? Where is that located? Is it that thing on the intake box, or in my case on the pipe before the intake box?

Yes^^