My friend's 93 se has a fluctuating idle when he is in neutral or park. It will just go up and down from around 2,500rpm to 1,500rpm. I know there are numerous possibilities for this, but could you guys help me out in identifying them. I know newer engines have a IACV that could cause this, but I am not sure about 93 accords. I know a decent amount about Hondas (civics mainly), but he doesn't and really needs some help. Please help me out if you can.

 

Okay check your timing if that's okay then there's a screw where the air intake right between where the tub and the intake is connected, on your left on the intake there's the screw you could adjusted it. hope this help good luck.

 

Do not touch the idle speed adjustment screw. Try looking for vacuum leaks and check the coolant level. If the coolant is low top it up. If you can't find any leaks and the coolant is free of bubbles try cleaning the IACV. The F22A does have an IACV as well as A FITV. try cleaning them before making any adjustments to factory set screws.

I think you'll find that if you know how to work on Civics, Accords are very similar.

 

Awesome, thanks for the quick replies guys. What areas should I spray with carb cleaner to try and identify leaks? I've never had to diagnose a vacuum leak before.

Also, carb cleaner is used for cleaning IACV's, correct?

 

Any vacuum hose junction or end, around the injector seals, throttle body and intake manifold gaskets. Usually not a gasket problem unless they have removed parts recently. Yes carb/throttle body cleaner is the best way to clean the IACV and IAC & FIT ports in the throttle body. There is a very good write up in the Accord FAQs sticky.

 

Thanks again for the help. One more thing I should add. He says it is not happening at idle (at stop lights, etc) it only happens in neutral and park.

 

Automatic transmission? If it is an A/T it could be that it's not doing it at stops signs probably because the engine is still under a little bit of load????

Check the usual suspects and then look at TCU/ECU or electrical problems.

 

Yeah, it is Automatic. Sounds good. I'll make a list of all the possibilities and check it out when we can. Then we can go from there. Thanks for the help.

 

My '93 LX automatic does the same thing. I've cleaned the IACV, FITV, booster valve, throttle body inlet bore & plate, and adjusted the idle screw and checked vacumm leaks. No luck so far.

The problem occurs only when the outside air temperature is above 60F.

alacard - please post what you find if the problem is fixed.

 

Check if you EGR ports are clogging up? Could be only two cylynders are clogged wont cause stuttering until 3 are clogged

http://home.comcast.net/~em-engineering/T2T013.pdf

 

I had all 6 EGR ports cleaned too following the instruction from the link you posted. Still has no effect in fixing the fluctuating idle issue.

 

my f22b did the fluxuating idle and i found that my throttle body gasket was the issue it causes a vacuum leak. check your gaskets if you still cant figure it out

 

Thanks for the comments guys. I will update this when we try some stuff out.

 

I have a question though before I start troubleshooting. If I clean the IACV and/or the FITV and still no go...couldn't that mean that the entire valve is bad and needs to be replaced? How do I determine whether the valves are not bad?

Edit: I saw ghostAccord's post on checking FITV functionality.

One last question (I think), you mention to make sure there are no bubbles in the coolant. How do I determine if there are bubbles and how do I get rid of them/ what is the proper way to fill coolant?

 

Here is the link that shows you how to test the valves

http://www.cb7tuner.com/vbb/showthre...highlight=idle

 

If you want to check if the IAC valve is actuating you can hook up a ground wire and tap the (+) terminal with a 12v source. If the IACV clicks when you give it 12v then it's working.

Edit* ^^^^Or read that link...lol

 

All of my questions are answered, and I've got a nice hefty list of stuff to check. Thanks for the help guys. With all of the info out there on this, this must be a very very common problem.

 

That it is. The Accord forum usually gets at least one or two posts a week asking about a problem with a surging/erratic/bouncing idle. If you looked throughout all of H-T there is probably an idle related thread posted every day. It is one of the prominent Honda annoyances. Bearable but still an annoyance.