On 02:24 PM 07/12/02 -0400, Ronnie Cruz said...
>I had it checked by a mechanic and he said he doesn't have an answer to
>me.
>
>I'll describe the problem as best as I can.
>
>As soon as the engine warmed up, my car will start to show the idling
>problem. RPM is usually in the 3000 RPM range. I will then experience
>hesistation usually during shifts. The person that I bought it from
>said that oxygen sensor is broken.
>
>Thanks.
>
>Ronnie
Is the Check Engine light on? Typically if you have a bad/defective O2
sensor, the Check Engine light will come on after the engine has come up to
operating temp.
I would also check the ECU for any error codes:
http://resource.crx.org/maintenance_engine_ecu.html
A bad O2 sensor will throw an error code 1 on the ECU.
One thing I did learn not too long ago (from the local Honda dealership)
was that the engine will run with the O2 disconnected. The engine will
just run in a rich mixture/condition. Obviously performance and fuel
economy will suffer. If your car is equipped with a catalytic converter
("cat" for short), it's life will also be shorten.
O2 sensors from the dealer is pretty expensive. Somewhere in the mid $100
(USD) the last time I checked (which was back in 1999). I picked mine up
from the local Kragen AutoParts store for around $45 (USD) and it's been
running fine (passed all my smog test/checks since 1999) ever since.
If no error codes are being thrown by the ECU, I would look for a possible
intake leak around the manifold. On a previous non-Honda car I use to own,
I had a leak at the base of the throttle body. It was enough of a leak to
cause erratic idle but not large enough to cause any backfiring.
I was able to find/detect the leak by spraying some carb cleaner near the
base of the throttle body ~ be careful when doing this and you don't want
to spray directly on the throttle body but almost parallel with it. If
there is a leak, the carb cleaner will get sucked into the intake manifold
and the engine RPM should rise.
On yet another pervious non-Honda that I use to own, I had a bad fuel
injector o-ring and so air was being sucked down into the chamber.
Some other things that come to mind could be (in no particular order):
- Crank sensor
- Throttle angle sensor
- Coolant sensor
- MAP (Manifold Absolute Pressure) sensor
- Intake air temp sensor
- EAVC
- O2 sensor
Since your mechanic can't seem to figure it out, I would suggest that you
go to another mechanic or even the dealer and have them do a diagnostic
check. Having the dealer do a check does not obligate you to have them
perform the repair. Just be sure that you get a pretty good detailed list
of what they find wrong.
BOL!
Robert K. Kuhn
CRX Owners Group President (http://www.crx.org/southcal)
1990 Honda CRXsi (http://drive.to/jiggy)
ICQ # 3714283 (nickname: godzilla)
