srudiger

ok i just picked up a 2000 civic si with the orig b16 for the most part its stock.

ok so when i start the car it revs high and stays at a un-normal high rev untill it gets warm then it will jump down then back up and will continue untill the car is shut off.
i took it to S.A.G.E and had a leak down test and compression test because i had thought my head gasket might be bad. i thought there was oil in the coolant but it turns out the preveious owner had put fix a leak in the rad and thats all it was. the comp test came back 170 195 210 205 and we figured it was the rings in the 4th cylinder but wasnt to bad only 9% leak bye i was told they come factory with like 5% and although its not good its not horrible so back to the idle prob i took my iac valve off twice cleaned it and nothing when i pull the iac plug the idle drops its still seems to surge a little but only maybe 100 rpm also the previous owner for some reason swapped he cluster with an ex auto one so i dont know exactly where the rpm are cause it is off. so i decided to just go ahead and buy a new iac valve so i replaced that and at the same time drained all the coolant replaced with new also did spark plug tube seals valve cover gasket and new spark plugs and still same exact surging. this is my only car at the moment and this is just getting old and help would be apprecaited

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srudiger

also if i pull the intake and cover the hole in the tb while surging with my finger it idles perfect till i pull my finger back off then it goes right back to the surging

mycargoesbwahhh

Here's a few things you could try if you haven't already. As you probably know, the Idle is suppose to be somewhat high at warm up, so the extra air coming in is okay. When the ECU gets the message to lower the idle, due to the Coolant reaching Operating Temperature. It discovers that the IACV can't compensate for the amount of extra air. Adjust the Idle Set Screw. Turn it to the right, so it's a 1/4 turn back from being completely screwed in. I've ran into that issue a few times, and that fixed it. But, I can't guarantee that this will fix your issue, just throwing some pointers out. Also, a few more things you could try:

- Unplug the Coolant Temperature Sensor and see if that helps with the idle.
- Unplug the Throttle Position Sensor and see if that helps with the idle.
- Try Cleaning and Adjusting your Fast Idle Thermo Valve.
- Check to see if there are any air pockets Stuck in your Cooling system.

But out of all honesty. Try and adjust the idle set screw first. May just be set a little to high, and it might just be letting too much air into the IACV. Hope this helps some.

srudiger

thanks alot man i tried unpluging my tps and nothing also my car does not have ftiv i already ddi rrsearch on that i am going to try re bleading the coolant again tonight and the idle set screw, also im cleaning the tb tonight and putting it back with a new gasket to see if that helps any

83Stang5.0

Yeah if cleaning the IACV didn't help, then try adjusting it. The IACV itself could be bad, but when you start replacing sensors like those, if you aren't buying new stuff, you might open a bigger can of worms.

I spent alot of time on my old H22 w/ stock ecu trying to fix the lopey idle, cleaned everything, replaced everything, not much change. Finally got a chipped ECU and I just disabled IACV and a few other non-essentials, motor idled perfect.

Fabrik8

Yeah, you don't need any of that pesky idle regulation stuff.

srudiger

well i already bought and installed a new iac and changed my coolant when i replaced it because the previous owner had used fix a leak in the rad and it was really sticky so i put all new in today i will be working on it but i will try the screw and re-bleeding the coolant system also im cleaning my tb and replacing the gasket i heard some people were getting leaks from the tb gasket and i fugured its only 2 bucks might as well just change it while im cleaning the tb. So as i explained before bye covering the whole and it idling perfect doesnt point out a specific problem?

srudiger

UPDATE: today i cleaned the tb and put a new tb gasket tightened everything back down bled the coolant again and still doing the same thing. also adjusted the idle screw all the way in and 1/4 the way out. also sprayed around with carb cleaner trying to find a vaccum leak and nothing happened. so now i was curious maybe it is the ecu i heard it is rare but it could cause so when i went to look at the ecu it seems to be a chipped ecu there were no markings on it so i could not tell what type ecu it is but i am about to upload a picture. so ? is do you guys think it could be the ecu aslo if so is there anyone that has a spare stock 99-00 b16 ecu i could plug in to check, and also what else am i missing to try

srudiger

83Stang5.0

Take the top cover off the ecu then take a picture, running a stock p28 ecu on a B16 prob isn't helping your issues.

If it is chipped already then, you can just get someone to re tune it and fix your issues.