Afflicted1

I have had this car for 3 years. The idle surge only happens on a warm restart. When the car is restarted the idle is above or around 1500 so its surging. Then it finally calms down to 750.

I have replaced:

3 different new coolant temp sensors.

the throttle body gasket 3 times,

the IACV gasket is new honda oem.

THe intake manifold gasket is OEM and replaced.

The injector manifold seals are new and OEM.

The map sensor , tps has been tested with an ohmmeter and are in the correct ranges. Tps is set correctly and has smooth voltage up and down. Ive tried a new tps, no change.

All vacuum lines have been replaced.

Distributor has a new coil, new cap and rotor.

Ignition wires are new, spark plugs are new.

Car has intermittent power loss some days and others runs nice.

Idle was set correctly at 750 rpm when warm. It does idle and stay there once the warm restart surging calms down. On cold idle its perfect and never surges.

I have a NEW ecu.

Brand new waste of money 214$ idle control valve with oem gasket. STILL SURGES.

I have cleaned all harness plugs with electrical spray cleaner i have wiggled wires... NO check engine light....

I have a new oem fuel pressure regulator

Fuel pressure is good.

4 new injectors and seals!

Replaced map sensor o ring and tps gasket

Spark plugs are ngk. New.

Have electrical spray cleaned out the map sensor. No change.

Have blocked off various vacuum sources. Still surges...

Cooling system has been bled so many times... dont mention that please. Also have put dye in the coolant.... no leaks...

Heres the issue im not understanding.... with no air leaks... (ive checked the brake booster and evap system for leaks too , still surges) Why is the idle so high ONLY on a warm restart to start the surge until it settles to 750 rpm if there are NO vacuum leaks. NO air being sucked in when car is idling warm from IACV hole. My car does NOT have THE FITV. (99 civic ex) I had the car smoke tested by the way at a shop and wasted 100$ Please dont tell me "spray for leaks" thats not the issue here. Also, ive done a block test. im not losing ANY coolant. Headgasket is good. Compression was even across all 4 cylinders. and lets just say this.... EVERYTHING IS NEW and set correctly except im running on the original map sensor. If i unplug the map sensor the car dies.. Seems normal ?

Ive heard the distributor can cause this having play in the shaft. Is this true?

After i changed the iacv gasket the car didnt surge for 4 days, now its back again worse than ever... Everytime i redo gaskets etc and reset the ecu the idle smooths out for a day then comes the surging...

Believe me when i say ive exhausted possibilities here. I **** you not all these parts are NEW and the surge has never changed, no matter what i adjust or how i set the idle. Idle is at 750 rpms when warm. Throttle plate fully closed, have cleaned the throttle body out... my car has no egr valve...

I need serious help.

Former User

Auto or manual tranny?

Are any CEL codes thrown?

Have you tried adjusting the idle speed exactly as detailed in the service manual.

Afflicted1

Auto tranny. WHich i also rebuilt.

Yes no offense ron. But i listed all that. It says no check engine lights and i do follow the manual. I have the service manual and the haynes.

Former User

What tranny and what specific procedure did you use to set the idle speed?

Does the CEL work? Have you checked for codes by jumping the service connector or hooking up a code reader?

Try this:

When the engine has the surging idle, remove the air intake system and use your finger to cover the hole inside the TB leading to the IACV. Does the idle speed drop and the surging stop?

Afflicted1

Have already done that. Many times. There is no air being sucked from the IACV hole when its idling warm. THats how its supposed to be.

My tranny is a b4ra.

Yes checked for codes many times. Never is any. I know the cel works.

i set the idle by running the car hot for a while driving it around then come back and adjust the idle warm with no loads on the car using my scanner to see the rpm. Set it to 750. When i unplug my iacv though the engine goes haywire and fast revs... but the idle control valve is the 2nd brand new one ive tried !

Brand new ecu dude. I listed that. Plus 2 junk yard ones. Same **** happens. Warm restart surge. Yep the cel works. When i unplug the iacv valve when car is idling smoothly warm the idle goes haywire and throws a code. Anything i unplug throws a code. Ive tried so many things i know its not the ecu.

Former User

Dude, I know you're frustrated but chillax and settle into a productive tech discussion.

It's unclear whether you are answering the specific question asked. Is the surging and high idle problem eliminated by covering the IACV hole in the TB?

Afflicted1

I can send videos of anything you wanna look at. I wanna know about the distributor question i asked. And have you ever seen a map sensor cause idle surge? THe damn map sensor is the only thing i havent replaced! I know the #1 reason is vacuum leaks on a honda for idle surge. Believe me ive researched for YEARS. I have threads saved from the honda training manual that has critical idle info and ive done these things and it says my problem is too much air. Well.... i promise you... after a smoke test, all new gaskets, and many "spray for leaks" tests there is not too much air. The engine purrs at idle forever once it settles down after the warm restart surge.

Afflicted1

No its not eliminated the surging continues when my finger is on that hole. I answered all your questions as much as i could. I am relaxed.

Former User

This^ single test rules out an IACV, ECT, TPS, and air in the cooling system problem.

I know you think you've rule the following out, but you should refocus your effort on looking for a vacuum or intake air leak.

Afflicted1

Ok wait. My car has the hole that is for the idle screw and the hole for the iacv only. If its surging and i put my finger on the iacv hole theres no change. If its surging and i put my finger on the idle screw hole, it will calm down. But isnt that because its just upsetting the air /fuel ratio?? How does this point exactly to a leak, especially with new gaskets and a smoke test? (i dont say these things rudely, i apologize for my tone in text)

Former User

This^ is the problem. Air is leaking past the idle adjust screw. Fix that air leak and you will fix your idle problem.

Afflicted1

Not the hole that you adjust the idle screw in. I mean the upper port inside the throttle body above the port to the iacv. What you're thinking i meant, i have already put in a new idle screw/o ring

Afflicted1

Ok my car doesnt have the fitv, it has a port on the throttle body on the upper and lower. THe lower sucks air when cold for my iacv. The upper is the only one sucking air when the car is warmed up and that one stops the surge BUT its manufactured into the throttle body. Its a big hole like the iacv hole right above it inside the throttle body. WHats that for?

Former User

That's the hole for the MAP sensor. The MAP sensor O-ring is leaking. Replace it.

Afflicted1

Can i send a pic to make sure we are on the right page here??? I did already replace the map sensor o ring as stated in my first post with an oem seal.

Afflicted1

brb pic time, stay here or ill die without you ron! ha

Former User

You can upload a picture to your post.

Click advanced edit>manage attachment>upload>submit

Afflicted1

Uploaded with ImageShack.us

Afflicted1

Pic is sideways ... so i poorly ghetto labeled them. That top port calms the surge. This is inside the throttle body.

Former User

I believe it's the air bypass hole for the idle adjust screw. I think 96-00 Civic TBs have separate holes for the IACV and idle adjust screw whereas 92-95 Civics had a single hole for the IACV and idle adjust screw and a separate hole for the FITV.

Afflicted1

Ok. Thats what i assumed too but then got confused by what you said. So if that hole calms the surge what does that mean? Also my car has intermittent power loss. When the power loss is present its not super severe but noticeable. THats when the idle surge is at its worst. WHen i replaced the iacv gakset the idle and power was perfect for 4 days... till yesterday the idle came back shitty as ever and wouldn't stop the surge till i put the car in gear. The power loss also is back. My engine has a slight shake to it at idle ive noticed. THis is why i asked about the distributor. Car starts up everytime without hesitation. Never stalling or starting problems. Is the engine shake normal? WHen i redid my tranny i installed all new engine mounts. Seems like a slight misfire.

Former User

If covering the upper TB port with your finger eliminates the idle problem, then the problem is a leak past the idle adjust screw and its O-ring to the bypass passageway into the IM. It's that simple. Fix the problem and then go from there.

Afflicted1

Bypass passage way clogged? alright i guess ill try another o ring for the idle screw, but i have replaced it with an oem part from my local honda.

Former User

Not a clog but an air leak. There's air leaking past the screw.

Afflicted1

If this works ill send you a chocolate cake with your name on it. Thanks. Ill be back for sure to report if it fixed because i wont stop till its solved.