Fast Idle Valve

[w261w261]

Last Friday night, as the car was idling (f.i.motor), it ran up to 1400 rpm, then quickly fell to 1200, up to 1400, back to 1200, etc. I stopped it and restarted, same thing. After driving off it was fine, and hasn't done it again since.

I assume this is the fast idle valve acting up. I had a new one put in a couple of years ago, and at that time the mechanic said he hadn't had good luck with cleaning them, so I got the new one. Has this been the experience here?

thx

[shepherd79]

yes, it is very common for honda engines.
the easiest fix is to adjust it yourself.
since you have 89 accord i don't know much about adjusting the fast idle on them, but it should be very simple. you should need just a screw driver.

[w261w261]

There is an adjustment for the idle. But I was asking about the experience of people regards cleaning up the old idle valve, or whether I should just buy another one. It has only stuck that one time, and has been fine ever since. But I figure that if it will do it once, it'll do it again soon, so I might as well attend to it.

[AccordEpicenter]

if you need to, get one from a junkyard for like $5, buying a new one from honda is alot. You can play games with taking it apart and stuff but i dont reccomend it. The EACV can also get messed up and make it do this, and ive also had my throttle adjustment screw back itself out and give me a bouncing idle, so basically its a vacuum leak, weather its from the fast idle valve being homo or the eacv or even if your intake manifold gasket is bad, wierd things cause it too.

[1987HondaAccord]

So where is the fast idle valve? or the EACV (what does that stand for?)? I'm having the same problem with the idle going up to like 1700 and then falling to 1200. any more info on this would be great. thanks!

[NXRacer]

if you've installed a custom intake then you'll have idle problems because your MAF sensor is unplugged from the stock intake piping.

If you're still running with the stock intake system, check your MAF sensor vacuum hose for leaks. My car idled up and down like that until i re-routed the vacuum line to the intake manifold.

[AccordEpicenter]

uhh NX we dont have a MAF... do you mean the breather tube?

[NXRacer]

we do have a mass air flow sensor. its a remote sensor located in the top secret black box on the firewall.

[BaDPiSToN]

It's the MAP sensor... not the MAF sensor.

The MAP sensor is the Manifold Absolute Pressure sensor.

[rsxguy]

Last Friday night, as the car was idling (f.i.motor), it ran up to 1400 rpm, then quickly fell to 1200, up to 1400, back to 1200, etc. I stopped it and restarted, same thing. After driving off it was fine, and hasn't done it again since.

I assume this is the fast idle valve acting up. I had a new one put in a couple of years ago, and at that time the mechanic said he hadn't had good luck with cleaning them, so I got the new one. Has this been the experience here?

thx


hey dude iam new to these cars and iam having this same problem can yall please show me a picture of how this looks like would appreciate it alot thanks

[w261w261]

Hello, and welcome to the forum. On the top bar of the home page go to "search," then put in the term you want to look for. On this topic, there's plenty of threads. Try "eacv," or "idle valve," or "fast idle." There's no better way to come up to speed than by reading what's been posted in the past, and you'll find that people are more cooperative in answering your questions when they see that you've put some effort into it prior to asking.

I can't speak for the carbed cars, but on the f.i. ones the fast idle valve is by the back of the air plenum. It's a couple of inches across, and has a little round cover on it. Two small coolant hoses go in and out of the bottom, although they're hard to see without removing stuff. When it starts to fail, some people say it can be adjusted, but I just bought a new one.

It would also help if you would provide the exact model of your car. Since the carbed cars are different than the f.i. ones, and there are some year-to-year differences, it helps people to assess what to tell you.

This forum will be a big help to you. It's a great tool, but like all tools, you have to learn how to use it to get the most from it.

[2oodoor]

old posts ftw!!
A good thing to keep in mind, with ANY electronic fuel injected car... A regular maintenance item is cleaning the throttle body, butterfly in the thorttle body, and if you do a thourough cleaning with professional grade TB cleaner and a toothbrush.. some of the solvent will find it's way to the idle air control device, whichever type your car uses.. and these idle problems will most likely be resolved. In a lot of cases though the idle air control device will need replacing because they have crud behind the pintle stem which meters the amount of air allowed in the mix at idle, and in most designs it is unreachable with cleaner.

A professional grade TB cleaner: examples would be BG, BG simply disolves everything and keeps it loose enough without evaporating, until all the matter has exited the engine exhaust. Seafoam makes an equally effective product, the key is a product that cleans, disolves the carbon and oil cake and does not evaporate before the process is finished.

[Whiter]

I havnt really searched around old topics but basicly my deal is i have a 89 accord exi and it idles around 750rpm and once in awhile normally in traffic in the middle of the day it just drops and kicks back up and i press the gas and it drops and cluggs a bit like a old chevy and then shoots back up, it also drops to a stall and im stuck looking like a fool that cant drive standard not to mention it has a serious starting problem and needs a few seconds to sit before cranking otherwise it will just sound like the battery is dead which i have tested and is not.. any tips for my issues. i will get some pictures up of my car real soon the paint job is pretty horrible but it isnt that bad in pictures.

[w261w261]

I havnt really searched around old topics but basicly my deal is i have a 89 accord exi and it idles around 750rpm and once in awhile normally in traffic in the middle of the day it just drops and kicks back up

How's the coolant level? Also, make sure you don't have any air bubbles in the system. Open the bleed valve (by the thermostat) and let it spit until the coolant doesn't have air in it.

[Beanshonda55]

to check if it is the fast idle valve all you have to do is have your car idle and pump on the brake for a little bit and if the idle goes up or moves form the brake then your fast idle valve is bad.

[LX-incredible]

to check if it is the fast idle valve all you have to do is have your car idle and pump on the brake for a little bit and if the idle goes up or moves form the brake then your fast idle valve is bad.
Incorrect. The idle will always raise when the brake is pumped. When the pedal is depressed, the booster uses engine vacuum to assist in braking. When the pedal is released, it lets in air to release the vacuum pressure on the diaphragm. Where do you think that air eventually ends up?

[Whiter]

coolant is fine the radiator might be rotting away in the middle tho but i dont think this would be the problem

[w261w261]

coolant is fine....

Did you bleed the coolant system? The level could be fine, but if there's a bubble or two in there, when those bubbles get to the valve it will screw it up for a moment. It doesn't happen all the time, if there is just a little air in the system.

[Whiter]

i have the next 2 days off i will try to fix the problem with my cars retartedness and then i will start a new topic to let you all know whats up. im going to do the steering rack and replace the power steering pump and maybe pick up a rad from the scrap yard and swap them out

[Beanshonda55]

Incorrect. The idle will always raise when the brake is pumped. When the pedal is depressed, the booster uses engine vacuum to assist in braking. When the pedal is released, it lets in air to release the vacuum pressure on the diaphragm. Where do you think that air eventually ends up?
Yesterday 10:10 PM my bad i guess that makes sense now.