93 Accord idle speed

Has anyone monkeyed with the cooling system recently? Such that air may have got
in?

Make sure the level in the cooling system reservoir is correct. Then consider
doing a careful purge of air from the cooling system. See <a style='text-decoration: underline;' href="http://www.autozone.com" target="_blank">www.autozone.com</a> for
free repair guides specific to your car. Make sure the fan comes on twice, as
the directions usually say. This may take 40 minutes or more with the car
idling.

My 91 Civic's cooling system had air in it, and I believe it was messing up the
EAC valve (a.k.a. idle air control valve). This valve has a coolant port which
was running empty on my car. I had symptoms like yours (though my car is a
manual transmission), and ultimately, the air purge fixed it right up.

How old is the PCV valve? I doubt this is the problem, but for the record, the
springs on these do wear. They may open and shut fine, but not throttle
correctly. If yours is the original, replace it. I'm changing mine at least
every 60k miles now. (The original made it to 140k miles without ever being
checked. I replaced it on a whim and my fuel mileage shot up over 10+% and has
stayed there.)

"Elliot Richmond" wrote
 > My 1993 Accord has started oscillating between 900 rpm and 1600 rpm
 > when warm and in neutral or park. In gear it idles smoothly at around
 > 950. In neutral the engine revs up to 1600, drops suddenly, seems to
 > almost stall, then revs up again.
 >
 > I just had the car in for 150,000 mile service. The shop replaced the
 > plugs, rotor, air filter, and fuel filter and a couple of oil seals as
 > well as some mechanical problems not related to the engine. They did
 > not replace the PCV valve, which would be my first guess, but I
 > checked it and it seems to be okay. They did replace the PCV valve
 > hose, but I do not know why. They did not charge me for it or mark it
 > on the invoice. Maybe it was leaking.
 >
 > This is the four cylinder, 2.2 L fuel injected engine with automatic
 > transmission, USA version and USA emissions equipment.
 >
 > Any suggestions will be appreciated and acknowledged. I want to know
 > if I can blame the shop before I take it back.
 >
 >
 > Elliot Richmond
 > Freelance Science Writer and Editor<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: 93 Accord idle speed 

On Tue, 16 Nov 2004 00:14:54 GMT, "Caroline"
wrote:

 >Has anyone monkeyed with the cooling system recently? Such that air may have got
 >in?
 >
It's possible. I will check at the cooling system and replace the PCV
valve.

Thanks for the suggestions.


Elliot Richmond
Freelance Science Writer and Editor<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: 93 Accord idle speed 

Did that work for your car because i was told it could be the throttle position sensor. It could also be a diffrent sensor.
 >> Stay informed about: 93 Accord idle speed 

I had same problem and it is throttle body sensor. You just need to take it off and clean it good. If your throttle body was cleaned it got the sensor dirty. As far as pcv valve, just take it off and shake it, if you hear valve move inside it, its still good. If not you can just use some carb cleaner and squirt it in there and cover both ends and shake it and it should loosen it. But then again a new one is only 2-5 bucks.
 >> Stay informed about: 93 Accord idle speed