I just bought a 1994 Accord EX for 1,000 bucks. New engine with 40,000 miles, same transmission, with a different head.

The problem with the engine is the idle, in park and neutral the car will fluctuate idle between .7 and 2 rpms and drop back down to .7 and repeat. If I turn on the A/C it will stop the idle, and when I turn if off, the idle will remain the same. I also noticed when I have my amplifier, lights, and inside light on, the idle will change if I turn one of them off. I cleaned my IACV, it is working properly (hear a click when plugged/unplugged, idle change,) the FITV is sucking air during idle, the EGR lift valve and other EGR thing on the manifold was cleaned out .. I am running out of ideas): I also noticed it will randomly idle higher then normal, and sometimes will idel lower when the A/C is on and higher when its off.

Thanks(:

 

The FITV should only draw air when the engine is cold. If you plug the FITV port on the throttle body when the engine is warmed up, and the idle stabilizes, then clean then tighten the plunger in the FITV.

Also, did you bleed all of the air out of the coolant system? That can cause the idle mess up.

 

how does one purge the air? should that be a first step to take to resolve any idle issues? my 97 idles really low and rough with the a/c turned on.

 

When engine is cold, open radiator cap. Loosen bleed valve on top of thermostat housing with deep 12mm socket.

Any air in the system will spit out of that valve. When a steady stream of coolant comes out, close the bleed valve. Top off radiator. Reset ECU, by pulling 7.5 amp radio/backup fuse for a minute in engine bay fuse box, so the ECU can relearn the idle. Put fuse back in. It will take maybe 10 minutes to do this.

 

Oh, yeah.

One other thing you can do is clean the throttle body and both sides of the throttle plate. Use throttle body cleaner some rags and maybe an old toothbrush to remove the buildup of grime on there. Definitely reset ECU after you do this as well.

 

Someone mentioned this before in relation to cleaning the throttle body - it was said that you should know your radio code if you are resetting the ecu.. any idea what that's about?

 

Whenever power is shut off to the radio, a security feature kicks in where the radio will not work unless you enter a code into the radio. That is if you have a a Honda stereo.

Its a 5 digit code that was on a card slot with my owner's manual. Someone wrote it down in my owner's manual too.

Its good to have that code, because when the battery dies, you will need that code.

It won't affect how the car runs.

EDIT: If you can't find the code, call a local honda dealership and ask them what you need to provide them to get the code. It should just be the VIN on the dash board and some proof of ownership.

 

Disconnecting the battery is one brute-force method of resetting your ECU. When you do that, many year/version stereos have a security feature where the stereo requires a security code to be entered before it will work.

Some years (98-02 at least) have a particular fuse you can pull to reset the ECU without interrupting power to the stereo.

 

When you pull that 7.5 amp radio/backup fuse on the 94-97 accords, the stereo will need the code reentered.

 

I finally got around to cleaning my FITV, and realized that I never reset my ECU after cleaning my IAC, FITV, Boost, EGR Valves .. and everything else involed with idle. Ha .. Thanks for the help, I am going to reset the system now and see how she runs. Thanks guys, and yes I did bleed my radiator fluid, but I did not have my cap open while doing so, so I might get back on that.