scubacamper

1993 Accord LX 190k

Loping idle after warm up - Idle Air Control Valve? If so, is it serviceable?

If not serviceable, is aftermarket sufficient?

slowcivic2k

A warm lope is usually a vacuum related leak. When the FITV acts up it over idles cold, and will bounce.

I would start with trying to find a vacuum leak myself. The IACV can act up, but when it does, its because it cannot remove any more air from the engine (IE vacuum leak).

Start with finding a vacuum leak, and then check engine base idle with the engine warm, and IACV unplugged. Adjust your throttle bleed screw as needed to reach 450rpm warm. DO THIS ONLY AFTER you find any vacuum leaks.

takyonxxx

one reason is fast idle thermo valve screw it to clockwise, if not other is air boost valve, disable air input of this item and see if te loop still accure. isolved my problem by repairing this air boost valve. this valve is marked as green at below link
Honda IACV explained - Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com

sorry for my english..

cafrog

I say it's the IACV. FITV shows issues at cold start....not running temp. Yes it could be a vacuum leak but if nothing has been messed with recently, I say IACV is stuck and gunked up. I've had issues with my old Bswap and with my current Kswap (from HMO).

Take IACV off and see how it looks inside. Carburetor cleaner will help clean it. Not sure what your IACV looks like but I have taken the black plastic electrical portion off IACV and soaked the metal portion in carb cleaner over night.

Or get lazy and buy one from a recycle or new OEM from an online dealership. I would check it first and see if it looks dirty inside. If it looks fine, check for vacuum leaks.

takyonxxx

please check this topic..
https://honda-tech.com/honda-accord-...valve-2493942/

scubacamper

I found a great video on this topic:

scubacamper

Update:
I removed & cleaned out the IACV after I saw how much those things cost (egads!!) - I sprayed it down with some carb cleaner and actually let it fill up with carb cleaner and sit for a few minutes.

After re-assembly, the loping idle is for the most part, gone. After driving the car for about 20 minutes, I noticed the loping has returned but only intermittently now whereas before it was like clockwork - very rhythmic.

I screwed down the plastic adjuster on the fast idle air control valve also.

If I end up having to purchase a replacement part for either valve, is there a certain aftermarket brand to choose, or to stay away from? Is this another one of those "go with OEM" scenerios?

scubacamper

How did you get the electrical portion off? Mine looks like it's got a pentagonal allen-type wrench fastener (as opposed to a hexagonal on a typical allen wrench).

cafrog

Ones I've done had a 5-pointed star shape. I used my dremel and a cutting disc. I made a linear groove across the screw head so I could loosen it off with my screedriver. Pretty easy just take your time and be steady.

Lost Again

Like a "torx" bit?

scubacamper

Sort of. It's really more like an Allen fastener except it has 5 sides instead of 6.
Amazon has a tool set for $13 that has the pentagon bit...

cafrog

Yes but a pain in the butt 5-point instead of 6-point torx

I bet you can do the same as I did. The screws aren't that long or torqued down real hard.

scubacamper

So I was able to remove the pentagon shaped fastener opposite the black plastic cap, but I cant figure out how you got the plastic cap off! I dont want to break it...
How did you get the plastic actuator off?? (I call it an actuator because it seems like this is the electric portion that moves the spring when it receives a charge....

cafrog

The ones I've done....the black part comes off. It is magnetically attached.

How does the inside of the IACV looking?

scubacamper

Did the one you worked on look like this?
I hope this link works:
http://m.oreillyauto.com/mt/www.oreillyauto.com/site/c/detail/BWD0/31061/02169.oap?year=1993&make=Honda&model=Accord&vi=116 7241&ck=Search_iacv_1167241_1176&keyword=iacv

cafrog

The link didn't work.

Let's try to make it simpler. Keep the electrical portion on and just spray carb clean inside the holes and use a cheap metal brush (or old toothbrush) and clean it out as best you can. Rinse it with more carb cleaner when finished. Use a rag and spray carb cleaner on it to clean the holes on the intake manifold.

Make sure it's completely dry before re-installing. Air compressor can make this faster.

Hopefully it's your fix.

Edit: Don't forget to burp the coolant system. Rad cap off and let car idle for awhile. Could be 30-45 minutes. Kick back and watch fluid in radiator through inlet (use a flashlight if needed). Be ready to fill it as the thermo opens and rad losses coolant.

Here's a video I found. Not too informative but hunting idle accord like yours (this one is a 1990). Look at the dirty IACV.

https://www.google.com/url?sa=t&sour...3wb9cKRzE6AxDg

scubacamper

I've cleaned it out twice now and it's still got the "hunting" symptom. I definitely need to bleed the coolant but it seems like the iacv might need additional cleaning somehow.
This is a 1993 lx accord.
2.2 f22a1 auto trans.
When I apply 12vdc to the terminals of the iacv, the actuator does retract the spring inside but I'm not sure if it's retracting the proper distance, as I'm not sure what the proper distance should be...
I've also replaced the 2 temp sensors and switch right underneath the distributor...

holmesnmanny

With the car warmed up, unplug the connector for the iacv and see what the idle rpms are.

Test for ohms across the iacv pins. Should be 8-15 ohms.

cafrog

It has a Fast Idle Thermo Valve?

With intake pipe off, (inside TB) there are two holes? One high one low. If so, when idle is hunting, you could plug each (individually) and see how idle reacts.

Edit: burp the coolant soon. Might be the fix.

scubacamper

Here is a video of the disconnecting effects:

Ohms = 12.2ohm one direction, 5.2ohms the other (pos/neg placement)

scubacamper

I have plugged the holes in the TB and nailed the issue to the lower hole, which I'm pretty sure is the IACV, correct?

Also, I think you might be right about the coolant - I'd like to pick up one of these to make it a bit easier:

scubacamper

I've been reading about using ONLY Honda OEM PCV valves - I have a (new) aftermarket unit on there - surely, this isn't the cause...is it?

cafrog

Lower hole....man I can't say for certain but D and B series motors have the upper hole for IACV and lower hole for FITV. Try to trace it down and see with sensor is for the bottom hole.

cafrog

I watched the video.I see code 14 with the flashing. That's code for IACV (that you unplugged). Reset the ECU and see if code 14 comes back.

Based on my knowledge....IACV unplugged at running temp should idle around 450-500rpm. At least with other Honda motors....that's the way you set idle...by getting that window rpm with idle adjustment (w/IACV unplugged). Then shut car off, plug back in IACV and reset ECU.

holmesnmanny

It really looks like your iacv is bad. If it had a vacuum leak only it should still be idling higher with the iacv closed because it would still be pulling in air.

These things are really completely unserviceable outside of cleaning the outer metal mesh of any debris. Once you still spraying stuff inside, especially carb cleaner based products it will swell the inner seals and kill it.

Grab and oring and spray it with some carb cleaner and watch what happens, especially when the oring is hot.