Here's the Problem. PLEASE HELLP!

My 94 accord ex with JDM H22 swap idles up and down when it reaches operating temp. like most people's car (honda) do when they have this disease. I have searched, read, and tried what most people did that work for them, but no luck for me.

First of all the car have no cel (no check engine). Here is what I already tried: clean my IACV, clean the FITV, and screw down the white plastic screw in the FITV all the way in, clean the EGR, drain the coolant/refilled/bleed coolant (for any air pocket in coolant system), adjusting the idle with the screw in the throttle body by unplugged the IACV, check for vaccum leak, but still the idle continue bouncing up and down.

I then replaced the FITV, IACV, and the throttle body with working ones from another H22 motor, but the idle still bounces. So I know it's not the IACV nor the FITV.

When car warms up, I plug the FITV hole in the throttle body, the idle still bounce, but when I plug the IACV hole, the idle dropped low, but the car still running. When I plug both the FITV and the IACV holes in the throttle body, the idle again drops low and continue running (means IACV still working). When I block the throttle body completely the engine stall and dies (correct me if I'm wrong--no air leak).

If I blocked the IACV hole in throttle body completely the idle drops low, when block half-way where it only suck in little air, the idle drops and the engine idle normal, but if let go (keep hole open) the idle rose and started to bounce again (think the engine is taking too much air). I tried adjusting the screw on the throttle body all the way in for minimum air suction with the method of disconnecting the IACV sensor, still not fix.

I have tried what most people said to be their problem, but it doesn't seem to work for me. Now I'm running out of hope and don't know what to do.

Anybody have any suggestions or could till me what they did that work for them that I haven't tried?

 

2 things i would try.

new PCV valve (that fixed my surging idle)

make sure your throttle cable isnt overtightened (if it is it can act like a vacuum leak)

 

What ecu are you using? I've read about people using an auto ecu in a manual car and having this problem as a result. Try resetting the ecu.

https://honda-tech.com/zerothread?id=1058474
https://honda-tech.com/zerothread?id=1098640

 

The throttle cable is fine, but I will look into the PCV. Thankyou for the advice.

As for the ecu, I beleived it's an manual P13, at first I didn't have the surging problem, some how it just appeared.

 

Same thing happened to me. My temp gauge was ALWAYS very cold though in the winter. After the cold weather passed, i changed my thermostat and it was fine after that. So that might be your problem too???

 

I checked the PCV today as 93egsdan said, and it work fine because when I clamp down the PCV hoes the PCV click( which indicate it work fine).

About the thermostat, I'm not sure, but it took a long time for the fans to comes on. and the temp gauge never reach half-way. So dont know if the thermostat is still good or not. Even though the coolant hoes and the motor's very hot the fan wont even comes on for a very long time. But I will check on it.

Thankyou for the advice.

 

my pcv valve did the click too when i pinched the hose.


i replaced the pcv valve and it started idling properly.

then my pcv valve hose collapsed and it started again, replaced that and it fixed it.


so i would try replacing the PCV anyways...its like 2 bucks


while your at it, go ahead and replace the cap/rotor and ingnition wires. and do a valve adjustment. couldnt hurt

 

Thanks for the help. I will try that and see what happen.

 

I had the same problem, I bought a throttle body gasket that did not have the cut out for the IACV, so when I turned the car on, it chugged and stalled if I didnt give er gas, but once warm, It ran great. SO took off the gasket (cause that cant be good) and now im back to stupid idle... already changed pcv. This seems to be a very comon problem that you see here on HT..
Good Luck, let us know how it goes

 

Dang. Still no luck. I've replace the PCV, but still same thing. need more help.

 

I don't think that just because the motor dies when you cover the TB that you don't have a vacuum leak. A small leak can increase the idle enough to start the cycle but not be large enough to sustain combustion. Any excess air that enters the motor can cause this idle surge. Vacuum leaks, 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. I had a starting boost valve that was leaking through the diapham that caused mine. Something like that can only be found with a vacuum pump/guage. Anything that has a vacuum line running to it can cause this problem if it won't hold vacuum, not just the vacuum lines and gaskets. This includes EGR diaphram, Boost valve diaphram, cruise control, MAP, Intake bypass valves, Purge solinoids and others.