hello everyone, hope somebody can help with my problem, 94 accord f22 eng. at trans w/ac. all of a sudden the engine idle starts to go nuts, at P or N, the rpm fluctuates between 900 and 2000 rpm's no warning no check eng. light, there are no codes, driving the car on street or frwy. there is no problem, just the idle, can't pass smog check here in cali that way. Help!

 

Welcome to the forum,I would start by cleaning your throttle body,use a throttle body spray cleaner not a carb cleaner,spray it down good inside and out,let it sit for a few then crank it and with the throttle cracked slightly to keep the motor running spray directly into the throttle body,this will loosen any gum build up and lube the linkage.

 

Don't waste your time or money on the cleaners and junk the common problem with thfor this issue 99% of the time is know as the idle control vavles usually controlled by the Engine coolant aka anti freezeusually located on the intake manifold happens on hondas, with age or milage in them....trace coolant lines from the thermostat housing to the intake manifold usually have too step control vavle setup and has a plug-in on it. trust me try this fix first it will save you lots of time and money in the long run. Let me know when you get it fixed if this dont work looking at lot more money, or simply unplug the sensor and bump idle down to 500 rpm reccomended by honda but usually for the testing of the idle control vavle.

 

Great news people, my son's accord problem fixed. It turned out to be the fast idle valve. this valve is mounted to and under the throttle body. just remove throttle body turn it upside down and there is the valve, 4 bolts hold this on. but we only removed the cover closest to the firewall there are two screws that hold the cover, remove this cover there is a plastic, will call this a nut because this plastic piece is supposed to hold the guts of this valve together. when we took off the cover I turned the throttle body on its side and the pieces slid out, I cleaned off the little bit of carbon deposits out thats when i noticed this plastic piece had threads, looked inside the valve body and saw threads in it. put the pieces back into valve screwed in the plastic nut, reinstalled the throttle body, started the engine and it ran perfect. thanks everyone for your suggestions they were very helpful. turns out this is a common problem with the accord especially one with high mileage. I'm going to call a Honda dealer and find out if this repair is good for the long run or will we need to replace the valve soon. at the dealer the valve sells for about 150.00 plus tax, not sure if you could find one elsewhere. thank you and bye for now.

 

Xylocor read my post dated 11/16 " problem solved". Thanks for your suggestion anyway.

 

Glad your problem is solved,and thanks for letting us know what the problem was,we all learn from your expierence.

 

Something else that comonly causes a rolling idle on hondas is a vacuum leak since the ECU cant controll the idle it makes the Idle air control vavle turn on and off this is less noticalbe while in gear.