95 SC2 reving issues.

Okay, this problem takes a bit of explaining. When it's cold outside,
my 5spd manual likes to rev up on it's own. the colder it is, the
worse the problem gets. At it's worst, it's rev'ed itself up to 3800
rpm, while in neutral. When it gets that bad, it also accelerates on
it's own. If it's not doing it too badly, I can pump some gas in and
it'll settle down, or, oddly enough, I can stomp on the break which
will sometimes settle it down. It doesn't really do anything to the
car performance wise, it's mainly annoying, as I'm sucking gas, and
gas milage is the main reason I bought the car, and it's embarrassing
to be sitting at a red light and have my car roaring at 3500.

Also, once in a while, when first started in the cold, it'll die as
soon as I put it in gear. I always warm my car up. 10 minutes at least
(I live in Wisconsin, it's bloody cold in the winter). If the car
doesn't roar up as I was talking about previously, it will start and
sit between 1000 and 1500 as it should. This is when the other
problem happens. It will idle wonderfully. I get back in the car,
pop it in reverse, and as soon as I touch the gas, it dies. I let it
roll a bit, put it in first, it dies. The only way to keep it running
is to really hit the accelorater, and obviously, at end of my driveway
I have to stop. While stopped, I have to keep the clutch half way
depressed to keep it running. Once I can get the car into 2nd gear,
I'm good, but until then, it dies.

I've had the 02 sensor replaced, as my mechanic thought maybe that was
the issue. No luck. He can't think of anything else, and I really
don't want to take it to the local dealership to get it checked out.
Any ideas?

 

Another Sconny'! Last I checked the idle point was between 850 - 900RPM, and
it will spike and stay at 1000 if you have the A/C on or you just cranked it
over. It should quickly settle to the idle point though. Though as I'm a
newbie mechanic I don't know what else to say. It isn't the O2 sensor, since
mines bad and my car still performs ok, though after a heavy acieration or
highway workout the car wants to drown itself, and my gas mileage sucks.
Where the hell in Wisconsin do you live?

 

Sounds like the Engine Coolant Temperature Sensor.

Sounds like you need a technician, not a mechanic.

 

I've had the 02 sensor replaced, as my mechanic thought maybe that was

You need to consider finding a new mechanic who knows how to properly
diagnose the problem.

You've already replaced an O2 sensor which didn't fix the problem. A
diagnostic from your Saturn dealer would likely have accurately identified
the problem, and probably would have cost less than you've already paid.
I've had a problem or two over the years that I could not figure out myself,
and the dealer has identified it quickly and accurately. And I believe the
diagnostic fee was around $30 or so - cheaper than replacing ONE part that
doesn't need to be.

My thoughts on what to check out (plugging into the PCM and reading its
codes will go a long way): coolant temp sensor or the idle air control
solenoid.

Good luck,
Lane [ lane (at) evilplastic.com ]