m90polk

Alright I've been driving my civic around for almost a year with the ZC DOHC in it and when ever it gets very hot out the car has a surging idle.
Example 1: when I push the clutch pedal in so it is not engaged in a gear "neutral" the RPM's should drop but they instead go up to 1800 then it climbs within 3 seconds until it reaches about 4200. Also when I shift from gear to gear it will not drop in RPM's for that second or so.<--Only does this when it's real hot out high 80's+.
Example 2: The car when it is cold out or up unto the 70's will surge in idle from 900 to 1800.
It's seems to me like the throttle body is not closing all the way because there is no other way for it to get the air like that. I've already changed the vacuum hoses, cleaned the throttle body out, replaced TPS, cleaned the IACV.....so right now it would be helpful if someone could shed a little light on the problem. Here are some pics of the throttle body and the IACV, in the pic of the throttle body is that the fast idle valve and could that be causing the problem?

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YBLEGAL

Get yourself a Hondata Intake Manfold Gasket (or one of those ebay thermal gaskets are fine). Replace the throttle body gasket and intake mani gasket. It could be either of those. Also your fast idle thermo valve could be the culprit. There is a wax plunger on the inside controlled by the coolant temperature. You could plug the FITV hole for a while and see if it fixes the issue.

Just taking the intake mani off and cleaning it all up and replacing all gaskets would be my final solution tactic (and it's what I'm doing now on my car too).

edit: sorry that also includes injector o-rings and seals, EVERY possible point of failure on the intake system

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m90polk

Yeah I get what your saying but do you know if there is a fast idle valve on my car or do you have a picture of one for my car.??? Because I really don't think it's the gaskets considering if it was a vacuum leak it would be reving up and down whereas mine is just constant increased idle which seems like it has something to do with a sensor or signal back to the computer telling it that the throttle is open even though it's not which is making me think it's the TPS but I just replaced the TPS last week.....and I'm back where I started running in circles

YBLEGAL

Test the TPS with a multimeter. .5 closed, ~4.5 wot. No sense in replacing it aimlessly. It might also be the o2, if you think it's sensor related, but I'm not sure how to test it. When mine went bad, I had the convience of using hondata's dataloging to spot it.

Ya, your situation might be different than mine. that's just an idea for ya.

I can't tell if you've got an FITV in that picture, it's a little blurry, and I'm not familiar with that sort of style. Do some searches on google images and maybe you can spot it yourself.

Sorry I can't be of major help. Bumps for ya tho

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m90polk

I was looking around online and there is no fast idle valve for the EF's because the fast idle valve is on the bottom of the throttle body and they they don't have any there. But on the other hand they do have the "EACV" electronic air control valve which controls the amount of air allowed into the engine at idle...and upon looking at the pictures of these on the internet they all have a screen in one of the two port holes facing the manifold, mine doesn't which means it's probably got shit in it and the sensor is garbage. I've already cleaned it twice before and it always acts up so now that I have seen the screen I don't have that makes me feel better , I think I'll just order a new one within the next week and see what it does.