*** EK3 Non vtec IDLE Pattern Issue ***

[dluxfan]

Good day Tuners,

I have an ek3 99 model civic, auto tranny, non vtec with d15b engine everything stock. Vehicle was working fine with no problems at all whatsoever. Did a service and changed all the usual stuff it accustom to (engine oil, engine oil filter, plugs, air filter, fluids etc) and everything was fine and then also was advised to clean the throttle body as it was never cleaned before although car working fine, so the mechanic took out the throttle body and cleaned it using the Brass spray cleaner.

After installing the throttle body back into the car and startup, the car idled at 2,000 – 3,000 rpm on Park or Neutral and 1,500 rpm on drive or reverse. It was taken back out and thoroughly cleaned again and now on a Cold start, it starts up and idles at 1,500 rpm on Park and Neutral and 1,000 rpm on Drive and Reverse and Remains on those rpm levels ALL the time, even when engine is warm and no matter how long I drive the car it won’t go down to 1,000 rpm on park and neutral or less than a thousand rpm in the other gears UNLESS (When engine is warm) I must switch off the car and start back immediately, then it idles “perfect” at 1000 rpm on Park & Neutral and 500rpm on Drive & Reverse as it normally use to. I did a diagnostics and nothing came up and there are NO lights on the instrument panel at all…

Does anyone have any advice or know how to go about resolving this Idle issue?
Thanks...

[kamakazi]

Good Afternoon
From what little i know i will try to help you.

By removing the throttle Body did you by chance damage the gasket that goes between it and the intake manifold...Friend had a similar problem with his D15B (Its a VTEC but it should be similar).

Not sure if the Non-Vtec came with that Idle air control valve at the back of the intake manifold(like there is on the B16A). If that was removed and cleaned i believe it should be sprayed with some WD40 and again...depending on how old the engine is...the gasket should be replaced (mine was just brittle after 10 years and disintegrated) It looks like the number 8

Could also be a vacuum leak caused by age hardened rubber hoses

Those are the only things that come to mind based on the information you posted

Hope you get it sorted

[Vtec Vigilante]

on cold start the car suppose to idle at 1500, then drop to 1000 slowly when the car is warmed up. Have you checked for vacuum leaks ?. Its a "hissing" sound which causes poor idling. When the engine is cold and running spray carburetor cleaner around the suspected areas. Don't do this when the engine is hot. It could also be the FITV which is located underneath the throttle body. Have the mechanic clean it and set it back CAREFULLY with a large flat head screw driver to its original position. Another thing to clean is the IACV located at the back of the intake manifold.


http://honda-tech.com/showthread.php?t=1564019

http://honda-tech.com/showthread.php?t=1575913

[dluxfan]

Thanks kamakazi and Vtec Vigilante. I would try to service the IACV and hopefully it helps

[Vtec Vigilante]

no scn padna....hope you get thru