Saturn 95 sc2, idle dies on me..

In article om>,
says...
>
> Should i claen it with carb cleaner?

That will be fine.

In article om>,
says...
> Blau - I have to disagree with you on this one. The ECT sensor goes out
> "high" or "open". [snip]

High or open??? Wtf are you talking about Wavy? If its 10 degrees out or
100 degrees out how does the engine richen the mixture when it's cold?
What happens if it thinks its cold and its not? And did I say anything
about a shorted sensor? The ECT is like a variable resistor. For a given
resistance you get a corresponding temperature.

16,180ohms = 14deg
???..snip
3,520ohms = 68deg
???..snip
177ohms = 212deg
Where's high or open?


The OEM ECT Sensors used plastic tips. They would crack and deform and
start giving faulty readings. They can and should be replaced with BRASS
tipped sensors to correct this. Are you with me so far? If the ECM
thinks its 10 deg in the middle of summer it will flood the engine with
fuel and stall out!

Coolant Temperature Gauge Sending Unit (goes to dash for "analog"
instrument panels)
Coolant Temperature Sensor (goes to ECM)

Prior to, and a little during OBD II switch over I think, Saturn used
two ECT sensors. One is for the gage on the dash (if you have an analog
gage) and the other for the ECM (which would later pass the signal onto
the dash). Only when they were rewiring and retooling the car to fully
use OBD II did they phase out the Gage sending unit. By 1996 all cars
"had" to meet OBD II requirements and by 1997 I think they finally began
using downstream o2 sensors on Saturns.

BTW it is Bla or Blah, not Blau.

No. Use Throttle Body cleaner, a toothbrush, and a soft clean rag.

Throttle Body cleaner works much better than ordinary carb or fuel injector
cleaner.

Bob

"JaY" > wrote in message
ps.com...

BläBlä wrote:
> In article .com>,
> says...
> >
> > BläBlä wrote:
> > > In article . com>,
> > > says...
> > > > When i drive my sc2 the idle goes from 1000rpm down to dead stop,
> > > > expecially when i give it more gas then usall and stoping at a
> > > > light. I
> > > > changed the idle control valve, but no luck. Any suggestions??>?
> > >
> > >
> > > When cold or only after its warmed up?
> > >
> > > EGR or ECT sensor or Fuel pressure. Diagnosing beats replacing.
> >
> > when warmed up, is there anyway to check the egr valve..... i looked up
>
> EGR vavle may not be able to close. Clean out any carbon buildup.
>
> > the ect sensor but could not find one. anything else it might be called
>
> Engine Coolant Temp Sensor. 95 was a change over year, you may have 2.
>
> http://www.autoglossary.com/

Should i claen it with carb cleaner?

"wavy" > wrote in message
ps.com...
What you said about 95 being a changeover leaves me scratching my
head... The only way to tell the engines in my 94 and 95 apart is the
way the air intake routes into the air filter box and the difference in
the EGR - in 95 the EGR became directly electronically controled rather
than the vacuum diaphram actuator. They both have the same temperature
sensors in the same places with the same wiring configuration. Did the
95 begin using two O2 sensors? (I havent been down there long enough
under the 95 to notice if there was a downstream post-cat-converter O2
sensor).

There were TWO coolant temperature sensors on Pre-1996 vehicles and only one
in Post-1995 vehciles. One sensor went to the dashboard gauge, whiel the
other went to the computer. Thus it was possible to have the gauge read
accurately while the fuel misture was enriched for a cold engine, EVEN
THOUGH IT WAS WARM.

Hope this makes what was said more clear.

Bob

You're telling me something I knew already, Bob. :-)
I'm the temperature sensor KING, yo!
(I know more about the temperature sensors on 1994 Saturns than
anything else - which I admit really aint that much)
Blau Blau said 95 was a changeover year.
Not being a mechanic I guess I misunderstood what a changeover year is.
I would have thought *96* was the changeover year if they went to a
single temperature sensor configuration in 1996.
I discovered all by my little self what the function of each sensor was
.. I even went as far as to build a connector so that I could hook up to
a digital ohm meter and measure the resistance "live" while connected
to the vehicle.

Blau - Open Or High = infinate resistance or very high resistance in
the range of Megohms.
I've not seen one fail "shorted". If you were to short out the sensor,
would the engine think its impossibly hot? Why not? The firmware
apparently does not invalidate unlikely input!
That is where I got the idea that it might be "shorted".
The sensors I've seen go bad read such high resistance - leather would
be a better conductor. And when the ECM sees 10 or 50 megohms
resistance at the CTS does it think it's impossibly cold or does it
consider the reading invalid? It apparently does the former.

On a hot day the over-rich mixture doesnt kill the engine, it makes it
idle fast. I dont understand exactly why, but it does. Mine did.

Lets just say I'm completely wrong and you are correct. Mine are the
only ones produced that do this. Out of a million Saturns, my two are
the only ones that idle fast when the sensor is bad or high (or open -
like when you DISCONNECT it) and everyone else's is different, I guess.

****, I missed the Twilight Zone...

Bob Shuman wrote:
> "wavy" > wrote in message
> ps.com...
> What you said about 95 being a changeover leaves me scratching my
> head... The only way to tell the engines in my 94 and 95 apart is the
> way the air intake routes into the air filter box and the difference in
> the EGR - in 95 the EGR became directly electronically controled rather
> than the vacuum diaphram actuator. They both have the same temperature
> sensors in the same places with the same wiring configuration. Did the
> 95 begin using two O2 sensors? (I havent been down there long enough
> under the 95 to notice if there was a downstream post-cat-converter O2
> sensor).
>
> There were TWO coolant temperature sensors on Pre-1996 vehicles and only one
> in Post-1995 vehciles. One sensor went to the dashboard gauge, whiel the
> other went to the computer. Thus it was possible to have the gauge read
> accurately while the fuel misture was enriched for a cold engine, EVEN
> THOUGH IT WAS WARM.
>
> Hope this makes what was said more clear.
>
> Bob

BläBlä, sorry about the wrong spelling. I dont know how to make an
"a" with umglots...
If it makes you happy I'll cut & past it.
> BTW it is Bla or Blah, not Blau.
>

Oh - where is high or open? Its past the top of the page, WAY beyond
16,181 ohms...

> 16,180ohms = 14deg
> ???..snip
> 3,520ohms = 68deg
> ???..snip
> 177ohms = 212deg
> Where's high or open?
>
>