mudpuppy4life

hello my car has been doin the honda surge for some time now people are saying it could be something else? with that said i know the iacv has to do with coolant temps,there is a censor with one wire coming out of it that controls the temp gauge well i noticed it was broke but still making connection. the temp gauge works if you are not torquing the engine up so im wandering if that censor could be my issue and what is it called? thanks mike

eirigance

It's the "Fast Idle" valve. The valve needs to be screwed back in.


Posted from Honda-tech.com App for Android

mudpuppy4life

its already screwed all the way down and yes i know it takes the cold start high idle away

cstone

Post a pic of the sensor. I'm sure someone can identify it.


Posted from Honda-tech.com App for Android

mudpuppy4life

its on the back side of the intake upnext to the firewall held on with 2 10mm bolts has 2 1/4od hoses and one plug also has a small cylinder black in color on it

eirigance

Your iac might not be working? You can un bolt it, but "NOT" disconnect it & have someone start the car to see if the valve is working. It's on the back of your intake by the fire wall. Two 10mm bolts. Very simple.


Posted from Honda-tech.com App for Android

mudpuppy4life

i know what and where it is my question is the temp sender for the in-dash gauge is broke(loose connection) could that have a affect on the IACV causing the surge or do i need to spend 200 on the IACV?

eirigance

No. forget the temp sensor for a sec. "Test" your IACV. DON'T just replace it. Could save you $200

bernarddip

My 95 accord when i turn it on in da morning it turns on but da idle drops all da way like its goin to turn off then it goes right bac up it only does it when it is cold sometimes it turns off when I'm at a light on drive and giv it a little gas to take off it turns off is dat a iacv problem

mudpuppy4life

ok so take the 2 10's out fire the car up and watch for a valve to move behind the little screen? what should i be watching for to tell if its working or throwing an intermittin signal?

GhostAccord

That won't work all that well. Your car will have a rather large vacuum leak if you try to start it with the IACV completely removed.

Do you have a Helms manual for your Accord? It has the test procedures that you can do very easily to check the activation/function of the IACV.

With the ignition switch ON, engine not running, momentarily take a jumper wire and place it between ECU pins A9 (+) and A23. You should hear the IACV click. If it does click then your IACV is working and you may have an issue with your ECU.

And to answer your original question, Yes the coolant/engine temps do have a lot to do with the IACV activation. However, the single wire Temp gauge switch does not control the ECU temp circuit. That would be the 2 wire ECT switch that does that.

Air bubbles in the coolant system can cause an idle surge, as well as a vacuum leak. Check all of the gaskets and seals around the intake manifold and throttle body for leaks.

mudpuppy4life

ghost would me telling you its an intermitin problem? the part was put on by some shade tree mechanic is it possable to rebuild or fab a block off plate for the iac?

GhostAccord

Block off plates are very easily built. I have made them from sheet metal and cork gasket or 1/4" aluminum plate. EGR, IACV and FITV. However, if you decide to block off the IACV your idle and electric load compensation will be affected. Your idle will more than likely drop down every now and then. You will have to adjust your idle a bit higher to compensate for this.

eirigance

It will work to show the Valve is working. There is no need for all this If you turn the car on "Vacuum Leak" or not. The valve will still move if it works.

mudpuppy4life

if i make up a block off plate can i do away with the sensor compleatly? can i unplug the iacv and loop the coolant lines together to prevent coolant loss? where would i turn up the idle, by using the screw in the topside of the TB or with the throttle linkage? thanks

GhostAccord

Yes you can do away with the valve body and loop the coolant lines. You adjust the idle via the brass screw on the top of the throttle body.

Make sure to jump the SCS connector before you make any adjustments with the idle set screw. That will ensure the the engine is at base timing when making your adjustments. I would shoot for 700 ±50 rpm at first. Give that a try and see how it works. A 750rpm target for base idle may be a bit low with the IACV removed. You may have to go up to 8-900rpm.

mudpuppy4life

i grew up with a 900rpm idle pounded in my head lol as soon as i get a piece of aluminum ill make a block off plate, can i use the o-ring gasket on the iac now or should i buy a roll of gasket material?

GhostAccord

You can try and use the o-ring, I did. However if you want to be 100% you could buy some material as backup.

Note: removing the IACV will throw a code 14, this will not adversely effect your engines reliability or performance. However the CEL might get to be a bit annoying. You can ether keep the IACV attached to the wiring and zip tie it up out of the way. Or you could see if shorting the two pins with a 12K Ohm resistor/wire works. It should!

If it does work you could go back and splice the two IACV wires together with a 12K Ohm resistor as a more permanent fix.


Note:
12K Ohm ±5% = Resistor with Brown/Red/Orange/Gold stripes.

mudpuppy4life

having a cel light dont bother me any...im throwing one for the O2 sensor by the cat cause i knocked the honey comb out haha i love florida but big thanks for the help also is it possable to block off the sensor with the white thing that i have to screw back in about every 3 months? the fast idle valve i think its called

GhostAccord

Yes, DIY FITV block off plates are common.

mudpuppy4life

ok thanks so much man! this honda tech website is a money saver also help from goin bald at a young age!

GhostAccord

You're welcome!

holmesnmanny

The iacv has very little to do with coolant temps. The coolant lines that go through it do nothing more than help keep the valve from freezing in cold weather. If you want, take the screws off that hold the plate that the two coolant hoses go through and see what you find.

The coolant temperature sender simply tells the gauge what the temperature of the coolant is. It does nothing at all else.

The other sensor that is next to it is the one that tells the ecu what the temperature of the coolant is and this one is very important.

So you say you have a honda surge. I don't understand why you'd rather ruin your idle more by getting rid of the only thing that helps steady the idle(iacv) instead of trying to fix your idle instead. Your car is going to run like **** without the iacv there.

eirigance

Couldn't have said it better myself.

GhostAccord

Yeah, the coolant temp read by the ECU has more to do with the IACV than you give it credit for.

As far as removing the IACV causing the car to run like ****, that is false. Sure the idle may dip and rise under different load conditions. It won't constantly surge or pulse. And it is easy to adapt to. The IACV really has no bearing on how the engine performs on the road. Hence why it is called an "IDLE AIR CONTROL VALVE". It really has nothing to do with the performance of the car in motion. It's only function is at idle and during a moving idle under predetermined situations. @ a stop light.

I ran my car without an IACV or a FITV for a complete winter (-20) without ever having a surging idle. Or any idle issues for that matter. I simply adjusted the base idle rpm (without IACV now = regular idle rpm) to a level that would adequately warm the car and idle reasonable with electrical loads. Same test procedure for idle ether way.