1999blksi

My friend owns a 2000 civic coupe and he's had this problem for about a month now; I couldn't diagnose it as I have a 1999 coupe and I don't have this prob

When his car is cold his RPM sits around 1500 or so...then slowly begins to drop as the car warms up. Then when he's driving it, before it's fully warmed up, and he's shifting gears, the car's RPM will be normal until he's coming to a stop and he realizes it sits between 1200-1400 and then slowly drops down to normal (900 rpm).

When his car is fully warmed up, he experiences the problem but at a much lower rpm (1000) then slowly drops to 800-900.

Any input as to why this RPM won't just go back to 800-900 upon coming to a stop?

MPR

Most cars idle a little higher when cold, then it slowly drops down.

Look for a vacuum leak. Pop the hood when idling and listen for a whistling or hissing sound around the intake manifold.

chris_v2

not really sure what the problem is here... are you saying the it idles at 1400rpm for awhile then drops to 900rpm?

Either way, i think a throttle body service is needed. Make sure you get all the ports, the cable is nice and free as well as the plate

Norb

Check for vaccuum leaks, and give the AICV a good cleaning. Cleaned mine because it was doing the same thing, and that fixed it. Depending on the engine, it may either have a AICV of FITV. What motor is in the car?

chris_v2

it's iacv. And instead of taking off the iacv, I would recommend a throttle body service first. You can access the idle port very easily thru the throttle body. What your most likely experiencing is a sticking valve, plate or cable.

1999blksi

What is AICV and FITV? He has a regular d16y8 i think...

Throttle body service done at a shop or by himself? If so, what should I tell him to use and is there a DIY on throttle body cleaning?

gatherer

I don't know but that seems normal too me .. whenever I came to a stop in my EG it would always first hit 1000 then drop to normal.

and that cold weather stuff sounds normal too.

Nicotine

sounds fairly normal to me for the most part.....

if it was like 2000rpm then slowly dropped and idled at 1500 or so, i'd say vac leak for sure...

1000ish dropping to 800ish....seems normal in the cold...

fingolfin

sounds normal to me as well, I have a 97.

But if it bothers u, do what chris said... service the TB... u can do it urself... i'll see if i can find a DIY for it

fingolfin

http://www.digmyhonda.com/h/story.ph...ning_your_IACV

a crappy DIY for the IACV, but it will do

http://www.superhonda.com/forum/arch....php/f-94.html
its somewhere there... look for it...