Idle up and down, nearly stalls

[jayjr1105]

Just leaving for a weekend trip yesterday, I noticed while sitting in the drive thru that our idle would almost stall, then bounce up to 1200RPM or so then quickly settle down to 750 or so. This repeated itself every 10 seconds. No engine light, don't have my scan tool on me to check things out. Car drove fine for the 3 hour trip to the cabin. It actually went away completely and now idles fine. I've read that the idle air control valve can get dirty/stuck and it just needs a good cleaning, however when checking rockauto for this part, the part becomes obsolete once you get into the 3rd generation Odyssey (05-10).

This is on our 2005 Odyssey EXL with 142K

 

[aquariuscsm]

Funny you mention that. My friend's 01 Odyssey did that very same thing the other day. Has around 250,000 miles.

 

[mk378]

Drive by wire would not have an idle air valve, the throttle plate controls idling. So you'd clean the throttle body instead.

 

[jayjr1105]

Originally Posted by mk378
Drive by wire would not have an idle air valve, the throttle plate controls idling. So you'd clean the throttle body instead.

So basically disassemble and clean with carb cleaner and a toothbrush?

 

[MichiganMadMan]

Was the weather cold on that day? I've had that happen when there is a piece of ice where the throttle blade wants to land. The computer has a hard time predicting how much air flow it will get for a given throttle angle, so it does the best it can and gets into hunting. Could also explain why it went away after you cruised for a while.

 

[Mr Nice]

Originally Posted by jayjr1105
Originally Posted by mk378
Drive by wire would not have an idle air valve, the throttle plate controls idling. So you'd clean the throttle body instead.

So basically disassemble and clean with carb cleaner and a toothbrush?


Yep, lots of oily grime builds up.

 

[tcp71]

Was the AC on? Or defrost setting to blow on the windshield? Both settings will cycle the AC compressor and the engine will increase idle to compensate for the additional drag, especially at the stated 10second intervals. In defrost mode, it's to dry the air and keep the windshield from fogging. Sounds like a bit of overcompensation as it adjusts idle settings after a long highway run off idle.

 

[jayjr1105]

Thanks, I'll look into that but I don't believe I had any AC or defrost on at the time. It shouldn't nearly stall the car.

Carb, air intake, throttle cleaner pretty much all the same thing?

 

[eljefino]

Could also have an air leak after the MAF if so equipped. Crack in plastic tube, sticky PCV, who knows?

 

[JC1]

Originally Posted by jayjr1105
Thanks, I'll look into that but I don't believe I had any AC or defrost on at the time. It shouldn't nearly stall the car.

Carb, air intake, throttle cleaner pretty much all the same thing?


Use Air intake cleaner and not Carb cleaner. Give it a good spray and cleaning with an old toothbrush. If it's drive by wire. not sure if you can easily press the throttle plate up (Assuming there is no butterfly mechanism on the side of the intake).

 

[willbur]

Originally Posted by jayjr1105
Thanks, I'll look into that but I don't believe I had any AC or defrost on at the time. It shouldn't nearly stall the car.

Carb, air intake, throttle cleaner pretty much all the same thing?


Carb cleaner maybe too harsh and remove anti-stick coating. Get the TB specific stuff

 

[MarkM66]

Something to be ready for.

If you move that throttle blade, you'll probably have to do the Honda Idle relearn procedure.

 

[jayjr1105]

Originally Posted by MarkM66
Something to be ready for.

If you move that throttle blade, you'll probably have to do the Honda Idle relearn procedure.

How so? How would the car know I moved the blade? Negative battery terminal removed and cleaned it pretty good yesterday. Re-assembled everything and it's running just fine.