MCHAccordLX

Hey everyone, I know I've been on here before, and I know there are billions of posts about this, but my Accord keeps getting worse with this idle jumping. IACV and FITV are cleaned, yet I'm still jumping RPMs. I used to think that it didn't do it in gear, but I'm noticing that (although not as bad) it does do it in gear, but ususally only one jump. If you have your foot on the gas at a low RPM, say around 2000 it may drop down and quickly shoot up, despite not moving your foot at all on the gas. I posted a video on YouTube, it's about 3 minutes long, my voice is a little boring and weird (I was sick), but try to get past that. I appreciate the help!

http://www.youtube.com/watch?v=XdtVcHyTlEg

I also talk about a noise in my aftermarket exhaust. Has anyone had any trouble with after market exhausts? I've tightened all the bolts, and made sure nothing was touching the exhaust (heat shield, etc.) and also the hangers were right and such, nothing appears to be vibrating and I spent quite a bit of time looking at it, yet I can't figure it out! THANKS!

SistoandNatania

I am having the same problem with the idle so I hope that someone knows how to fix it.

MCHAccordLX

Even after cleaning the IACV and FITV too? That's weird. I wonder what's going on!

zsudz922

what did you do to clean the iacv?try some good fuel system cleaner.my car did the exact same idle bullshit only when i was out of gear(m/t).i used some good fuel system cleaner and about a month later i was all good.also,you might just have to get a new one.
the exhaust noise may be the cat. converter if you did not replace that when you did your exhaust.the baffles inside it might be cracked or corroded making it vibrate at the certain rpm.im not so sure about the exhaust noise but thats just something you could check out.

MCHAccordLX

Hey thanks for the great help! Anyways, I cleaned the IACV and FITV using the instructions found in the Accord FAQ. I may try some of that fuel system cleaner. I heard Lucas is a good brand? Do you add that to a full tank of gas or can you add it to partial tanks? Gas is so expensive, I'd rather not fill a whole tank, but I will if you think it will fix my problem.
As far as exhaust rattle, I think it may be the cat. I'm going to try tightening up some of the bolts on the exhaust, just in case I've got a loose one, but it may be time for a new cat.
Thanks again for the awesome help!

zsudz922

yeah you can use Lucas.i heard a lot of people like that.put the cleaner in with a FULL tank of gas.

amckee

First, check for vacuum leaks. Anything with a vacuum line running to it must hold vacuum including the MAP, EGR, cruise control, brake booster, fuel pressure regulator,among others. Then check to make sure that there is about 1/4 inch of slack in the throttle cable. Then you will probably want to set your base idle. With the engine warm, unplug the IACV and set the idle to between 450 and 550 RPM. Kill the engine, plug the IACV back in and clear your ECU memory. Crank the engine and let it idle until the ECU settles down and you should be idling around 750 RPM. Any excess air that enters the motor can cause this idle surge. Vacuum leaks, leaking intake manifold, IACV, FITV, EGR not seating when closed, bad PCV, throttle cable too tight, and idle screw out too far can all cause a high idle. When the idle exceeds ~1200 RPM with the engine warm and the throttle plate is closed, the ECU cuts off the fuel injectors. The idle falls below the threshhold, the injectors cut back on and the whole cycle starts over again.

MCHAccordLX

So, I'll check for leaks and then adjust the idle? Maybe something got messed up with the base idle? Is it possible that it could have unscrewed itself similar to how the that white disk deal in the IACV unscrews itself? Thanks!

amckee

An improperly bled coolant system can also cause this, by the way. The small bypass lines that feed the IACV and FITV get airlocked.

flight50

my first guess was a loose or disconnected vacuum line. you can pull up a diagram on your engine from a helms manual, and check the lines. have you done any distributor work lately or in the past year. i had my ignitor spade connections come a little unattached to its post once. i went in with dielectric grease, retighting the spade referencing the diy on here, and i never had the problem again. but my surge was happening at high rpm, right when vtec would kick in and surge to 7-8k, yours happens at a lower rpm which sounds like a vacuum line. put you can check all leads that you can. a shop would get you for their time figuring it out.

MCHAccordLX

Thanks for all the help. It's more of a bouncing idle when it's cold than a high idle, so I don't really know what that means. Once the engine is at normal operating temperature and I put it in park or neutral, it idles just fine.
Interesting about the improperly bled coolant lines. I just had a block heater put in last winter. Is it possible over the course of 4-5 months that it could have made the problem get worse.
I started having this problem I'd say about 2-3 months ago and it only happened once. Then it happened again the next week, then it was happening once a day, until now when it does it any time the car has been sitting and allowed to cool all the way down.

SistoandNatania

Hey, I have been having the same problem with the idle jumping on my 94 accord. I watched your video on youtube and it looked identical to my car. I cleaned the IACV and the FITV and that actually fixed my problem. My d4 light was blinking and I cleaned and reconnected the Speed Sensor and that took away that problem so I hope that you will be able to figure out exactly what is wrong with your. Good luck.

jolitaly

i had the same problem with my 95 accord EX VTEC modded. a valve could be out in the IACV. even if u cleaned it, if that valve is out, it still will act up. take an air compressor hose and blow air through a port on the top and the side. one should allow air through and the other should be closed. also, pull the plug off the IAVC and ur car should drop in idle speed. if it doesn't it could be a faulty plug. as for ur exhaust, did u take out ur resonators? if u did, it's something with ur cat. really u should gut ur cat for best results anyways, but keep the box on there just in case u get pulled over...lol