QnzEP3

ok so i replaced my iacv brand new from honda about 2 to 3 months ago, i cleaned out the trottle body and got all the crap off of it, i took the air out the lines in the coolant and im having a problem that i thought would only happen with the older civics but im actually having the same problem i had on my old eg, my car when it sit sand is warmed up revs high, when it idles right it sits at about 800 rpm when i hit the gas quick it will hit 2000rpm drop down to 1000 and go back up to 1500 sit there for about 4 to 5 seconds then drop back down to 800, also if im driving and go into a complete stop it will idle like crazy with a constant rev, from 2000 to about 1200 then back to 2000 and back to about 1200 does it about 3 to 4 times in a row. idk wtf it could it but its driving me crazy, as far as the mods i have, i have a CAI aem, and thats really it. i have a check engine light for the primary o2 sensor that comes on once and a while, could it be a vacume leak? idk wat it could be, i never knew wat it was on my old eg either, but when i did the water pump and timing belt on my old eg it went away so i hope this has nothing to do with the same, please anyones help would be great....also when my car is fully cold and im in ny so the temp is about 10 to 20 degrees when i start the car i hear a grind like when u grind ur starter, i think the starters going but idk why it would make that grind noise

so to sum it all up
constant rev when cars standing still, grind when starting the car when its cold, check engine for primary o2 sensor, cold air intake and synthetic oil

josh's ep3

The grind is a common issue and is covered in a thread here in the section, just search for it. As for the idle issue, I'm not sure what it could be. The air in the system issue comes to mind but it seems like that's being taken care of...

josh's ep3

When you cleaned the throttle body I assume you took it off? When you put it back on did you replace the gasket? Check for vacuum leaks there.

QnzEP3

exactly how do u check for a vacume leak? and i replaced the gasket

iv

One way is to cover the throttle body and see if the car dies right away if it takes a second you may have a leak it really only works for large leaks though.

k20z1_types

Why did you end up buying a brand new iacv? Just curious. Its also weird that your cel comes on from the primary o2 sensor. Have you ever had a RH or anything on that deleted your cat?

I had this same problem but after i took my iacv off and cleaned it out it worked perfect and still has for 2 years now. I had i/rh/e/rbc/kpro tho so it sucked alot of oil through the pcv which can cause it to gum up the iacv and cause build up.

Was there any oil in the manifold when you took the throttle body off or did you notice?

QnzEP3

the iacv is about 4 months old, i noticed a little bit of oil in the intake manifold but not much (i heard this is normal for an ep3) this all started when i put bad gas in the car, i put bp gas and the check engine light came on for the o2, did put the gas in again and it was fine, then 2 to 3 weeks later i had no choice so i put bp again and the cel came on again for the prmary o2, i nvr put it since and now i only put sunoco 89 (plus) nvr had a racing header or anything that would delete the cat

QnzEP3

Anyone have any idea? The car rev at bout 1800 to 2000 rpms when car is rolling in neutral then goes down to 800 at a complete stop...plz I can't figure this out !

fasthatch95

your throttle body is not closing fully. try adjusting the butterfly screw down and clean all inside of it 4 a clean close. when itz cold the butterfly sticks slightly so the car idles high and then rpm drops realy low when the car warms up. A lil vacuum thru the throttle make that.

QnzEP3

Ok ill try that, should I put a little wd40 on the trottle ? So it moves a little smoother?

QnzEP3

Anybody have. Any other type of inside mayb? I d k wat this could be, I've driven 152 miles since Friday when I did the idle relearn and no check engine light yet, I hope I didn't oder that o2 sensor for nothing

kobeballer96

shoott. i thought bp gas was good??? i put 93 octane at bp everyweek

QnzEP3

Yea I thought so to, I used 2 put bp all the time but I guess it gradually f*ed my **** up

iv

Karcepts makes a block off plate that allows you to delete the IACV I use on my application and it works great even in cold weather. This will should fix your issue unless you have a vacum leak somewhere else.

Check it out here

http://www.karcepts.com/shop/categor...id_category=11

QnzEP3

Won't that throw a cel because there's no sensor attached to the iacv?

fasthatch95

trust me why did my si stay stuck at 2000rpms and tuch da gaz it stick even higher! when it warmed up it drop low az hell! Itz ur throttle body issue,take it off and basicly rebuild it like new. inside of ur tb plug the hole with the car runnen if it dies itz that leaking vacuum. Spanken new iacv need to get hot on the 1st time too. pull ur sensor frm it with car on if idle dropz its throttle vacuum problem.

QnzEP3

oo i heard if it dies then there isnt a varume leak

ek_sleepr

Check your TPS . if not check and see if your TB butterfly is working properly. it could be Both .

iv

I keep forgetting I have K pro

lmike6453

I'm surprised that no one else has said TPS sensor. Check that and I would also suggest checking/reseating your IACV if it's relatively new it could be a leaking gasket where it sits flush on the intake manifold. Besides that, check vacuum air lines by spraying them when the car is on and see if you see any bubbles/inconsistancy in the fluid on the lines.

ryanjvoss

I wuld say f that bp gas, i cant believe u bought a whole new iacv and it still has unsteady idle most of the time u can just clean those and they're fine. Just pressurize the system to vaccum test and locate any leaks or loss of pressure. AND STICK WITH SHELL GAS, THE BEST

v-dc5

try to reset the ecu

jelcivic

Have you disconnected the battery before the bouncing idle? If so you need to reset the throttle position. I had to do this with mine after I swapped motors. Start off by having the engine cold/disconnect then reconnect the battery. Make sure you have anti-freeze in the radiator/over flow. Make sure the climate control is on hot with the fans off. Start the car and hold the throttle at 3000 rpm until the fans have cylced twice. That will reset the throttle position. If you are still bouncing it may be the o2. I had the primary o2 bad and it would fall on it's face everytime I stopped. gl