Mechanics

HOW DO YOU FIX HIGH LOW IDLE

2003 Honda Odyssey • 124 miles

My Honda has been setting in the drive way for 2 months while my wife was out of state. It started right up and I backed out of the drive way to go get an inspection sticker. I put the car in park and walked around it to check the headlights and signal lights. When I got back in, I notice that I could not push the accelerator down as it was stuck. I pulled the hose from the throttle body and cleaned the gunk from the throttle body and butterfly. This is when the car started the high low idle.

I have checked all the things that you have suggested in your article and still no luck on fixing the problem. I have:

- Cleaned the idle control valve
- Replaced the idle control valve with new valve
- cleaned the PVC valve
- Checked vacuum booster by pinching hose
- used propane and carb cleaner to check for vacuum leaks
- checked all the fuses, under hood and inside van
- bled coolant lines
- checked voltage on TSC, which was in range
- cleaned power steering pressure switch connection and checked wiring for broken wires
- Pulled connector off of idle control valve while engine running and the high low idle is not as severe. Only 200 rpm variation between high and low idle
- put my finger over the hole in the bottom of the throttle body and the engine will die, but if I put it partially over the hole, the high low idle will stop
- cleaned EGR passages and ports in the intake manifold

I am on Christmas vacation and I have spent two whole days trouble shooting the problem with no luck. Any help would be appreciated as I am seriously frustrated and ready to give up.

Standing by….

Joe
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JHrametz
December 26, 2011.



Try this link for more information: http://www.2carpros.com/articles/engine-surges

Rasmataz
Dec 26, 2011.
Are you sure you got a good clean on that throttle body?It it was so dirty it wouldnt open then it should have been cleaned with some carb clean and brush. The opening of the throttle plate all around the butter fly the backside of the throttle plate. The opening of the throttle body etc should all be cleaned. Since it all started with the throttle body cleaning its ethier the dirty throttle body or you have a hose off etc.

Saturntech9
Dec 26, 2011.
Thanks for your quick response. I thoroughly cleaned the inside the throttle body with carb cleaner, brush and shop rag. Throttle works freely now.

Tiny
JHrametz
Dec 27, 2011.
Any codes in the computer have you checked yet?

Saturntech9
Dec 27, 2011.
No check engine light on to indicate a problem, but I have not flashed the computer with scan tool.

Tiny
JHrametz
Dec 27, 2011.
I would take it to a auto parts store and have it scanned for codes I always start by checking for codes if the lights on or not.
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Saturntech9
Dec 27, 2011.
I resolved my low/high idle issue today and I want to share my success with your readers. Here is what I believe happened in my situation. When I cleaned the butter fly with carb cleaner, some of the cleaner made its way into the idle control valve and loosened some of the gunk and cause the idle valve to stick in the open position. When I took it off to clean it, I removed the electronic part held down by the five point screws in order to have better access to the Phillips head screws holding the idle valve to the under side of the throttle body. It is impossible to correctly position the electronic part back onto the idle control valve shaft because it is magnetized and the shaft will rotate and cause the metal ear on the shaft to turn and miss the slot in the body of the electronic part. If misaligned, the shaft will held in the open position and a high/low condition will result. When installing the electronic part onto the idle control valve, it has to be done off the throttle body. In order to align the shaft in the correct position, I used the slanted ends of a wooden cloth pin to keep the shaft from moving while I install the electronic part onto the idle control valve. Once the electronic part was fasten to the idle control valve, I tested it to make sure it was operating properly by plugging it into the plug on the car and then turning the key in the on position without starting the car. If working properly, you could see the valve flutter back and forth one time each time the key was turned on. You could also feel the valve hum when the key was turned on. Of course, you need a friend to turn the key while you hold the valve in your hand.

I was also under the impression that the valve rotated like a motor when it only flutters back and forth and does not turn all the way around. Please share this with your readers and this tip will save the shade tree mechanic a lot of time and money. I lost two days of my Christmas vacation, but I probably saved 300 bucks for my efforts. I learned much in the process. I also have to give my brother the credit for the fix because he is the one who helped me diagnose the problem.

Tiny
JHrametz
Dec 28, 2011.
I was unaware you removed the idle air control valve but glad you got it fixed. Other users will see your post so it will be shared how you fixed it.

Saturntech9
Dec 28, 2011.

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