Hi I'm currently having a problem with the idle speed on my engine for some reason.

For one, when first starting the engine (cold start) the engine revs up to 2,000 rpm and then gradually comes down during warm up and then it's fine as I drive. Even when I have the car in gear ans stopping at a light. Again only in gear it works fine. But the problem persists when the car is out of gear and when I turn the engine off and turn it back on.

It will start up and the tach will hit 1,000 rpm (when engine is warmed up) and then will go down and then will fluctuate up to 1,000 rpm quickly then stalls.

What seems to be the problem? Is it the IACV? or in Honda term the Rotary Idle Control Valve?

 

Sounds like it to me. Have you tried cleaning it?

 

I don't know if I cleaned it or not. I remember removing the intake manifold to clean my EGR port a few months back and I took the IAC and cleaned the part were the coolant flows through. If your talking about that then, yes. If not then how are you suppose to clean it?

I know I need throttle body cleaner? But what do I clean?

Thanks for the reply btw!

 

the TB /throttle body is the big part where the air filter hose attaches and the throttle cables are attached to the side
Inside of that unit- on the bottem - is the IACV, it rotates to allow airflow changes at idle

with the throttle body off the engine- you remove the cover on bottem- remove rubber gasket- be careful or preorder a new one

undo holder tab for iac rod- remove rod- clean that carbon clogged chamber and the rod so it all moves freely when assembled

regular carb cleaner is ok for us- non chlorine suggested
we dont have a heater element wire in TB that requires the special `gentler` fluid

when you cleaned the egr - did you poke a wire coat hanger all the way thru from the valve end to the other end where all the crud was built up?
If you only cleaned the holes/ports at each end- thats part of your problem- still blocked.
and the egr valve itself- cleaned and lubed arm so it works freely?

IACV will make rpm jumping in most cases 800-1200rpm- when stopped at a light for example

careful the top cover gasket goes back on UP side up- port match against top cover to intake manifold, (looks right when placed on manifold) makes car run bad if on upside down--it fits- but blocks a needed port

 

@01tl4tl

Thank your sir! I appreciate it. That will be my project this coming Easter weekend. What's funny and kinda odd is that if I have the front defogger running when I start my warm engine, immediately after start up the engine seems like it wants to stall like usual but the clutch that activates the a/c compressor kicks on and the RPMs jump up a little. And no stalling happens. Not sure if the load helped out and the ECU had to accommodate for the extra power. Anyway, I have been allowing that to work for the time being until I can clean the IAC.

Thanks again bud!

 

Yes- the AC has an idle bump up switch to compensate for the load it places on the engine

the ac comes ON as the front defrost- since it dries out moisture fast, and keeps the ac in use during winter so its seals dont dry out

The freon type gas in the system contains a few ounces of special oil to keep parts inside lubed as needed, but it needs to circulate to work!

for those in nicer climates- DO run the ac for 30 minutes solid once a month in winter= to keep it ready for summer- expen$ive problems if thats not done

 

Do I have to remove the throttle body from the intake manifold or can I leave those two connected to clean the carbon clogged chamber and the rod?

Thanks!

 

some have been able to do the job on car- working on the bottem of TB
grab a mechanics small mirror and ck it our for yourself

but most remove the TB, or the entire manifold with TB and clean the EGR passages at the same time
Ones dirty- so is the other...egr due every 75kmiles,,maybe sooner on 99s

only requires a new TB to manifold gasket, and get an IACV cover gasket, just in case either tears

 

call acura care 1 800 382 2238x5 or ask your dealer service dept to run cars VIN for you
99s had a recall to work on the egr port, they clean the manifold as part of the deal
you could pay for iac to be cleaned then if needed

See if that was ever done, then proceed diy or dealer freebie