1996 saturn sl2

I have 1996 saturn sl2. 140,000 miles, decent shape, recently when the
car is started it revs up to about 3000 rpms, then idles down to about
1000 rpms. everytime i put it in gear it idles down but when i put it
in park or nuetral, it revs up and eventually comes back down It
usally idles high for 8-10 seconds then goes back. Any help with this
problem would be greatly appreciated. Thanks again.

 

In order of likelihood: 1) Thoroughly clean the throttle body using Throttle
Body cleaner, an old toothbrush, and a cotton rag. 2) If that does not fix
the problem, then take a look at the Coolant Temperature gauge and make sure
the needle moves normally. If it no longer moves to the upper middle range
when the engine is warm, then replace the Coolant Temperature Sender (CTS).
3) Also make sure the air filter and air intake is not clogged.

The TB should be cleaned regularly since it gets gunked up and the throttle
plate does not close completely.

Bob

 

I agree with the above, with the following possible exception. I'm not
sure about 1996, but my 1994 SW2 has *two* temperature senders: one for
the panel gauge and one for the engine computer. It is the computer's
sender that will mess up performance, even if the gauge's sender is
fine. So make sure that there is not a separate sender for the engine
computer, even if the panel gauge reads properly.

I had similar symptoms that turned out to be caused by the temperature
sender. It was tough (for me) to diagnose, because I did not know about
the second sender. I think it took the local garage only a few minutes
to find the problem. Also, just a bad connection to the sensor can
cause problems; be sure the inspect the connector on the sensor, and
make sure it is correctly seated.


--
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Ned Forrester 508-289-2226
Applied Ocean Physics and Engineering Dept.
Oceanographic Systems Lab http://adcp.whoi.edu/
Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA

 

I believe 1996 is when they went to one CTS ... I agree with verifying the
connector and connection are good, but the CTS design makes it very prone to
failure. When it fails, the controller/computer reads it as a cold engine,
so it calls for more fuel delivery via the injectors which is why the engine
RPM is noticeably higher. Another symptom of a defective CTS is a
significant reduction in fuel economy (MPG).

Good luck!

Bob

 

And if you haven't done so already, have the stored codes read. Autozone
will do it for no charge. It may give you an indication of what the problem
is (if a sensor is reading out of range), and quite often, it's better than
replacing parts based on guesses.

Lane
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