<mmdir2005@yahoo.com> wrote
> 89 civic with 220K miles on it.
>
> I think my best guess I've found out it that the Coolant
> temperature
> sensor
> could be the problem. Where is the Coolant temp sensor in
> my car?
> The manual has no picture on it.

Part #24 at
http://www.hondaautomotiveparts.com/...SUB+CORD-CLAMP

See also the drawing at
http://media.honda.co.uk/car/owner/m...SH200/5-56.pdf

Should be the same for your 89 Civic.

> what about Throttle Angle Sensor or Intake Air
> temperature sensor
> beside EACV?

The idle troubleshooting chart in my Chilton's manual for
your 89 Civic says the coolant temperature sensor (a.k.a.
"TW sensor") is the most likely cause. This chart appears in
the free online manuals for your car at www.autozone.com ,
under "Emissions Controls."

The Throttle angle Sensor and Intake Air Temp sensor may
cause other problems not consistent with your symptoms (so
far).

It could be the TW sensor. I think that's come up here
before and is in the newsgroup archives.

I'd still do the air purge. I'd still keep the EACV in mind.
These too have come up as the source of idle problems. Just
not sure if they cause 'engine cold' idle problems.

> Is Curly saying that driving the car with turn the heater
> on would
> purge the air out?
>
> My oxygen senor is about 4 years old!.

Is it OEM?