Hey all just wanted to ask about only thing on my car that has me scratching my head. My Ap1 has 28K.

70% of the time it idles right at 900-1K RPM once its warmed up. But once in awhile it will almost stumble idling or idle rough. Just did valves plugs full fluid change and problem is still there. It will sometime stumble as you press the clutch and the ECU seems to not want to catch the engine immediately till it gets real low then seems to sort it out. Its never died but it will stumble down to like 500Rpm sometimes.

Its just very odd. Car runs great most the time but once in awhile it kinda just doesn't want to idle smooth and can't seem to sort out where to idle. It seems to get worse when its been warmed up after being in traffic. Heat soak?

I was going to pull the idle control valve and look but with such low milage would it be that bad?

Thanks

 

It's a ~15 year old car. Regardless of mileage, things are likely dirty. All symptoms point to the IACV.

 

Ok thanks. I will just take a peek at it.

Read about MAP Whack? I read the thread but can't figure out people are saying the plugs loose or something or do you tap on it lol. I don't get it.

 

What steven975 wrote

 

I have the same issue, cleaning the IAC valve (including the roller valve) made it slightly better. I still get a slight dip in rpm when idling when up to temp every 20 seconds or so. Still get that low dip to 500 rpm occasionally when dipping the clutch whilst rolling.

It should be worth doing, it doesn't take very long.

 

I can't really tell you which of these things fixed the problem, but I think it was the combination of all of them. Here's what I did: Replaced MAP sensor and added zip tie, sprayed tiny bit of carborator cleaner into the opening below the MAP sensor, replaced PCV valve and cleaned throttle body and IAC unit, replaced spark plugs.

 

Thanks for help! I will tear into it today or tomorrow. Noticed on mine the throttle cable is in the way so gotta figure out how to move that without adjusting something lol.

 

I agree with this statement. Mine is also a MY00 with 175k miles and it was doing this low idle at times. Cleaned the IACV and it fixed the issue.

 

After I installed my intake on my car (for which I disconnected the battery during) I had shaky idle.
I thought it was the IACV for so long, and I tried cleaning it and had no success, map whack etc.
Turns out it just needed to relearn idle. After installing the intake, it seems I was driving at night mostly, as when I turned my headlights on, the idle would be perfect.
I reset my ecu the other day, did the idle relearn procedure and now it runs perfect as it should.

 

Hey all didnt get a chance to take it apart yet busy with work etc. I did push the MAP connector on tight with my hand and it has been idling perfect for last week never stumbled so maybe I need new Map recall deal.