idle it too high when coasting...

[California98Civic]

Originally Posted by mbrac

Thanks everyone for your input - I think I'm going to try cleaning the Idle Air Control Valve - since it's only affecting it when coasting - if that dosen't do it - I'll just replace it- cost from Autozone is $54 - no error codes - just noticed it since I became an ecomodder...

I recommend avoiding throwing parts at the problem. I did that once, and hopefully I'll keep my patience and never do it again. If cleaning the IAC does not work, test and troubleshoot before committing to a parts purchase. If you replace the part and the condition continues you will kick yourself for the lost cash and the unnecessary work. Do you have the service manual?

This novice's 2 pennies. Good luck!

[JethroBodine]

On my 98 Pathfinder, if I leave it in gear with the clutch in it will idle at 12-1300 rpm while coasting, if I shift to neutral it drops to about 650( once up to normal temp).

[3dplane]

Perfectly normal (unfortunately). Last time my employer gave me a focus to drive to...GM training and it did the same. It was automatic and even at 75-80 MPH when I put it in neutral,the RPMs stayed exactly where they were in D at that speed. (idled at 2000+rpm) As vehicle speed declined,so did the rpms to where I pulled it back to D the tac hardly moved as it seemed to rev match.
It has got to be an intentional ECU mapping. I thought it was annoying but never thought of it as abnormal.
Barna

[dcb]

fwiw, my 97 saturn likes to idle high when the car is moving and races a little on restart. I just waited till it was idling at about 1000rpm when warmed up and then unplugged the idle control valve. Takes a little extra footwork while it is warming up but otherwise it is perfect now.

[wakie]

a lot of car do this
the idle speed is higher to avoid engine stall in case of hard braking
the ecu need the speed sensor to do this
0 mph = normal idling
by the way, if you coast to a stop let the car in fifth gear the engine goes in fuel cut off it is better for economy than idle

[tru]

Originally Posted by wakie

a lot of car do this
the idle speed is higher to avoid engine stall in case of hard braking
the ecu need the speed sensor to do this
0 mph = normal idling
by the way, if you coast to a stop let the car in fifth gear the engine goes in fuel cut off it is better for economy than idle

that is not true for the focus, at least an 05' manual

[Kodak]

mbrac, does it idle this way consistently, or is it at all affected by engine temperature?

Mine will idle higher in really cold temps while the engine is below operating temperature.

Edit: It's not a Focus, but I figured any clues might help.

[SiVX]

Originally Posted by Kodak

mbrac, does it idle this way consistently, or is it at all affected by engine temperature?

Mine will idle higher in really cold temps while the engine is below operating temperature.

Edit: It's not a Focus, but I figured any clues might help.

All cars idle higher in colder temperature. The oil hasn't warmed up so it is thicker, there is more strain on the engine and a bunch of technical stuff that is way over my head. The point is, yes at first start and cold engine temps the car will idle higher. Always

[Weather Spotter]

my matrix idles at about 900rpm but I rarely idle it. I have a kill switch and use it regularly.