Question about strange Idling problems

[maestro]

Hey, this is my first time posting to this message board, and i apologize if this question has been asked before, but i didn't really see anyone post a question like mines,
so i had my 88 Accord Lx for over a year now and it's been my baby thru thick and thin, i had it's clutch and transmission replaced, and two new tires put on it, and just recently had it's ball joints and a control arm replaced.
But there's been one minor problem that's been bugging me for a long time, whenever i start it up when i haven't started it in several hours, it idles up to about 2500rpm and gradually increases to about 3000rpm...
Then when i let it run for about a minute or so i tap the gas pedal and it lowers back down to about 2200rpm. Then, when i starting driving it lowers back down and sounds normal until i come to a stop, and then it idles back up high again, probably to about 2200rpm again. So when i drive for about 5 minutes, it idles to about 1000rpm to 800rpm and it seems normal.
Ok, now when i drive on the highway across town for about 20 minutes and come to the exit i want get on and come back to a stop, it idles down really low. It would initially start off about 800rpm and then it would drop down to about 400rpm. Then when i am driving through residential areas, where i have to frequently stop and stop signs and stop lights, it would sometimes idle down to 200rpm! On few occasions, it would idle down so low that it would shut off and i have to start it back up!

I am not that good with cars so could someone tell me if this is normal or not and what can i do to eliminate this problem...do i have to let my car warm up for a while before i drive it? And i also notice that this problem happens more frequently when it is either raining or it is mild or cool outside.

[accordlxi2.0]

no! homey that's not mormal, i had a 86 lx and mine set to 200rpm's, ranned like a dream.
but in your case i have the same with my 88 lx, warm up, then i push the gas and it'll raise by itself and stay idled very high.

i have'nt worked on it due to me being in a leg brace and my starter went to sh!t on me.
but i would say the fast idle system is taking a dump on us, to take care of this you have to find a constant vacuum source, and attach the line's going from both port's of the fast idle unloader, to main vacuum source.
this should take care of it.

BUT does your a/c work's?
like when you turn on the a/c engine the engine idle goes up a little?

if so then i have another solution for you

the idle is somewhat being controlled by the ecu, but not to the point where it'll rev to 3,000 rpm's.

[maestro]

No, i don't have working A/C b/c i don't have a compressor...i drove it today, and i let it warm up for about 5 minutes before drove it and while it did idle down kinda low, it wasn't extremely low, so do u think warming it up got a lot to do with it since it IS a kinda old car?

['89AccordLX(Rus)]

Let it warm up to until it allows you to drop the idle down to about 1100 rpm, after that it should behave better. Mine doesn't like to be driven until I let it warm up a little. If I don't, the fast idle acts pretty strange and revs the engine to 2K until it warms up.

[hatchback86accord]

same thing happened with mine....some garage told me it was b/c i have an a/c but i dont have a belt hooked up to it...dont know if this is true or not... i usually just let mine run for bout 5 minutes before i would drive it. and its seemed to run fine... mine idled around 300 forawhile till i reset the idle screw on it

[A20A1]

Thats not true, the a/c with no drive belt would cause the car to run/idle better because of the lower loard.

I'm just going to throw this in here... but check your fluids oil/radiator...

Idle for A/C is controlled by a solenoid that bleeds vacuum to the Idle boost diafragm that allows the spring to press on the throttle and increae the idle.

could be a choke problem.