water temperature switches
 

What do the #1 and #2 water temperature switches actually do? I know they react to coolant temperature, but how/do they affect engine performance? The reason I ask this is because my x has some REAL problems warming up! Starts fine, but when it warms up really bogs down, and eventually stalls. If I let it sit for a few minutes then start her up, it runs fine!!! WTF??? Any info would lower my stress levels considerably!!! My rad doesn't have a #2 water temp switch on it, but my x must have originally have had one once, cause the wiring harness was cut, and the wire ends were twisted together!?!

I've a similar problem. My SE warms up early fine, then as the RPM's come down, about to 1200, it begins to "hunt" for idle. If I push the throttle lever off the cold idle cam, it goes straight to 800 and runs smooth. My theory is my computer is shot. It appears to search for 800 before the darn thing is adequately warmed up.

jeryj

Jeryj - different issue.

The SE's have the thermowax sensor that is mounted to the rear of your throttle body and has an actuator that moves the secondary butterfly valves to prevent them from opening during cold-start conditions (IIRC). If your engine warms up fine, but the idle never drops down, this could be due to several things;

1) the throttle body shafts or linkages are not moving freely, thus when the cold idle cam should allow the arm to slip free, the friction of the valves/shafts/throttlebody prevents the cam from sliding off - this will result in high idle after cold-start (does it do this during summer???)

OR...

2) The thermowax sensor has gone bad and will need to be replaced if you live in very cold conditions. This will be evident if you remove the heater hose lines going to the thermowax sensor (1 behind throttle body and another coming from the back of the water pump to the back of th throttle body). On my SE, this sensor is a green plastic appendage with a filter on one end, 2 heater hoses that attach to the bottom, and is mounted to the left side of the throttle body if viewed from the passenger side engine compartment. If you remove the 2 heater hoses, the TB now thinks the car is cold all the time - if the problem still persists, that could be it.

My bet is on #1, above, since SE's have a known problem with the TB needing to be lubricated often to prevent surging idle, high idle speed, lumpy/hunting idle, and lack of cold-start system bypass, as outlined above. HTH,

My 85 gsl has a #1 temperature switch but the wires on the #2 switch are broke off ( this is the plug that goes on the back of the waterpump with two wires hooked to it right?) I too am wondering what it is for. My water temp gauge only moves about a quarter of the way. I think this is good. Should I get this fixed? I see Victoria British sells them, But again what is it do?

Great info, LongDuck!

I kinda lost track of my message when I typed it. What I meant to allude to was I think my water temp sensors may be sending the wrong info to my computer. The computer is thinking the engine has warmed up to operating temp and therefore attempts to adjust the idle to 800 when the cold cam is still active.

It did this when the cruise cable was too tight also. A mechanical foul up as opposed to a temp sensor one. It was odd, though, the tach would sit there and go up and down 800-1200. The only thing wrong at that time was the cable was too tight!

I probably should pull my temp sensors and test them to make sure they are calibrated.

However, my thermowax crap may be bad, too. It may be the car IS warmed up and the twax is still causing fast idle. The throttle body is new but that doesn't rule it out.

jeryj

Surging is very common on the GSL-SE models (84/85). This is because there are so many inputs going to the computer that it tries to find the correct idle speed based on all the conditions and has to interpret many different signals to do so. The other problem with idle surge is the vacuum system which uses vacuum to handle the BACV (Bypass Air Control Valve - driver side of RE-EGI dynamic chamber) that has 2 systems tied into one - the BACV to adjust for air control during idle conditions, and the Idle Compensator (right side of BACV) which adjusts for engine loads to adjust idle. These two things respond to different functions, but are tied together, so compensation by one is feeding signals that tell the other to compensate, which often results in the two of them fighting it out to determine idle speed. whew...

A thorough cleaning of the BACV/Idle Compensator may either fix or cause the surging issue - go figure.

Also, as mentioned above, the sticking throttle plate shafts can cause surging as the BACV attempts to compensate for throttle plates that don't close completely. In this case, you'll need to clean the throttle body, clean the BACV and readjust everything (and I mean *everything*) to get it to idle smoothly again.

Somebody please post the link for the IDLE ADJUSTMENTS FOR GSL-SE'S please?

I own an 82 with no computer. Tried another #1 temp. switch from a wrecker, but it didn't do any good either (although I never checked it first). Any suggestions on what might be up?