1996 Saturn SL2

I have a 1996 Saturn SL2 manual transmission. It is a high milage car
(170,000). This week while stopping in traffic (with the clutch in)the
RPMs started fluctuating from about 300rpms up to about 3,000rpms. It was
recommended that I try a new PVC valve, which I did, but to no avail.
Today I was stopped at a light and when i tried to accelerate and release
the clutch. Even though I was pressing the gas peddle, it was like I
wasn't, thus it stalled. It has now done this every single time I am
stopped and try to go again. The only other VERY odd problem is that now
while my RPMs fluctuate while I am idleing, my thermostat gauge also
fluctuates. Any Ideas or recommendations??

 

You will soon be attacked with replies about the coolant temperature
sensor. But before that happens do a quick G search for more
information.

later,

tom @ www.URLBee.com

 

I have the same problem, and haven't bothered to figure it out yet.
Eventually, your SES light will come on and the error code will be
1406. This is for the EGR valve. I replaced mine and the problem
recured. I suspect that the engine is running rich (due to faulty temp
sensor?) and the carbon buildup jams the valve. I've noticed that my
mileage has dropped off since this occured and it is more of a cool/
cold weather problem than a warm weather one (for me, at least).
Buster
ps. mine's a 96 SL-1 manual with 110K

 

Is the throttle body dirty?

 

In my case, the throttle body was clearing about a year ago when I
replaced the EGR valve body. Keep in mind that my fluctuations have
only occured within the first few minutes of run time and only in
cooler weather. I can sometimes feel it coming and if I don't let the
RPMs drop below 3000, it will go away after a minute and I won't get
the SES light. It is always the 1406 code enough the valve is good, so
I'm assuming it's a system, not the actual problem.
Buster

 

sounds like the pcm is putting out to much voltage to your sensors,
id need to know more about the rpm fluctuations to say anything about
that.

 

On mine there was actually a collent leak above the collent temp senser.
Had the senser replaced before Firestone decided they couldn't figure
out what the problem really was. Not necessarly your problem, but
something to look out for.