Hello HAF Members,

My 1989 Accord has developed a 'high idle' seemed to happen after I took a long trip out of town and back. The car is still running fine, cranks right up, fast idles, but when the fast idle disengages it settles at 1200 rpm and as the engine gets warmer, peaks out at around 1500 rpm. I shut the car off in gear to keep the rpm down, it fast idles like this in park or neutral only. The benefit of this is I can have all my accessories on in gear at a stop light with no hesitation at all, but I'd still like to find out what is causing this fast idle.

I have observed the carburetor before and after cranking/warming up, on a cold start the choke plate is shut (not completely I'm pretty sure it is not supposed to be completely shut) and within a couple minutes it opens all the way, I tap the gas and the fast idle disengages, while looking down the barrels I can see that my butterfly valves or throttle plates seem to be shut all the way, I rev it up a bit and they still seem closed from what I can see.

There is a mechanic I've had my carb worked on before, he knows old Hondas, but it's a long trip and this car is pretty much my daily driver for work and school. Any advice or tips are appreciated!

Edit * I try to run as much Non-Ethanol gas in this car as possible, it does not sit. Also I have run Sea-foam through the tank and applied it directly down the carb throats conservatively, I have cleaned my K&N air filter, checked the vacuum lines, and lubricated the throttle body and Linkage.

 

sounds like a choke problem or a possible vacuum leak, check the jungle of vacuum hoses under the hood for disconnected or damaged ones.

 

I'm with the fast idle unloader.....I bet the little "port" has "gummed" up.

Give me a bit to see if I can find pic's and that.....high level, non technical - there is a "cone shaped thing at the front pass side of the carb. Going on memory there are two vac lines to this "cone".......one of the ports in the "cone" gets clogged. A small drill bit/bread tie - small amount of cleaner as you don't want to damage the diaphragm inside - and clean the port.

Again I'm getting old and slow on these....and my memory SUCKS.

 

Hey haven't been on, I've been quite busy but this morning I removed my breather and inspected all the vacuum lines. I also found that fast idle unloader and removed the lines to see if the ports were clogged up they didn't seem to be and the port closest to the carb won't allow me to go any further than 1/8 of an inch inside it which after messing with for a while I realized it was probably meant to be like that and there was airflow through it.

The arm coming out of the cone itself moves freely with little resistance and I observed how it slowly pulls the choke plate open as well, I lubricated the linkage there and reattached all the vacuum lines, the breather, air filter and cranked her up. It fast idled fine and the choke plate slowly opened while fast idling after a couple minutes I tapped the gas and the idle dropped to 1200 rpm, after fully warming it went up to 1500 rpm and refused to go to normal idle speed. I put her in gear and shut her off. I was a little relieved to see I didnt make anything worse :-P

 

Humor me. On the back side of the engine there is a two pin switch - it is around the oil filter but don't get confused with the oil pressure switch.

Pull the connector and jump the wire side of the connector. See if the idle drops once warm....oh and it might run funny when cold.