Ive searched and two things are talked about... A IACV and a fast idle control valve.. How do these things work exactly? I know what they are, but i need to know the hows of them...
Car is a 95 cx w/ 96 B18C-R motor. JDM P30 ECU OBD I wiring

My situation is when i start the car it idles fine... no problems. After the car starts to heat up (not full operating temp) the idle drops to like 300 rps... boggs realy bad. At normal operating temp (like 5 min of driving) the idle fluctuates between 900-1100 rpms... just back and forth... If i am rolling or not at a complete stop it idles fine.. right at like 1000 rpms with no bog.. Its ONLY when i come to a complete stop and the tires arnt moving at all... If they are barely moving i dont have the problem... What the hell?

So i need to know what these things do, so i can try to diagnose the problem. Yesterday i went in and took brake cleaner to the IM, TB and IACV and cleaned em up really good got everything spotless. New gaskets... Same ****. Didnt change a damn thing... The only thing i didnt mess with was the fast idle control valve, cause quite frankly, i didnt know where it is. I can swap a friggin motor in a car, do all the wiring but i dont know how these things work .

If anyone can help let me know, casue this idle is buggin me....

 

bump

 

you dont have a fast idle valve.
make sure coolant is bleed

 

dumb question: when you say it idles fine when your car is rolling, you're in neutral right?

anyway, besides the IACV and fast idle valve (that you've already mentioned), you may also want to check for any vacuum leaks in general. They can make it impossible for a perfectly good IACV to hold a steady idle.

good luck

 

[QUOTE=Black 2K]Ive searched and two things are talked about... A IACV and a fast idle control valve.. How do these things work exactly? I know what they are, but i need to know the hows of them...
Car is a 95 cx w/ 96 B18C-R motor. JDM P30 ECU OBD I wiring

okay, to explain to you want a fast idle valve and idle air control valve is:
fast idle valve: these valve is used during warm providing additional air for a faster warm - the valve is opening determined by coolant temperture. the colder the coolant is the wider the valve opening - and as the coolant gets warmer it decreases the opening of the valve.

IACV: this is control by the ecm/pcm - it varies opening based on engine load - this valve is a duty cycle type of solenoid(off and on) it a with DMM on the ground valve reading should be around 9-10volts.

but as for as your idle goes, I believe that your motor as a fast idle valve. to verify this look at your TB opening before the plate - if you see two air port you have a fast idle valve - a quick way to check if it's your iacv or the fast idle control valve is your problem block off the port that goes to fast idle valve - now if your idle goes away your problem is cause by fast idle valve. however, make sure that there is coolant and that the system is bleed. DO NOT ADJUST THE FAST ILDE VALVE THEY ARE SET FROM THE FACTORY. if there is coolant and no air present - a fast idle valve is needed - faulty pallet wax inside may have the cause.

hope that this was some help to you

 

i dont have a fast idle valve... what cars does this come on?????

i only have one hole in the TB that goes to the IACV.... Ok... so if the coolant is air free then it is the IACV??? have we narrowed it down??

 

no you dont have a fast idle valve, r motors dont have it.try swapping the IACV with another car to see if it works