While testing at the ECU, I noticed I get no Voltage at the ECU. Would this be a sign of a faulty Water Temperature Switch? It is hooked up to the rad. Searched, but did not see anything on this.
Thanks,
Chris

 

Go unplug the switch at the radiator and see what you now read at the pin 1H ....with the plug on the ECU and the key to ON or better.

If the water in the radiator is warm enough, the switch makes the circuit to ground and the voltage drops less than a volt. If the water is cold enough, the switch is not made and you should read voltage at pin 1H (or if at least one of the wires is off the switch).

 

With it unpluged, I get a reading of 11.7 volts.

My problem, my idle stays high for a very very long period at the first start up. It will drop eventually, but usually takes a drive around the block after letting it warm up for 20 minutes. That is why I am wondering about the Temp Switch.

 

The water temp switch on the whole a emissions item.

The idle problem is related to the thermowax device on the throttle body. Remove it and flush out the passages and also make sure the water hose that feeds it is unclogged/not crimped and also that the return nose for it is not clogged/kinked.

 

The water temp switch effects the RELIEF Solenoid(and therby the acv), and whether or not you get the approx 3000 rpm on startup of a cold engine for 17seconds

 

Where did you read that part about the relief solenoid, Hailers? Off of that S5 page again? Just wondering (sly grin)....

I guess if the water temp is below 60*F, the ECU will command the relief valve/ ACV to dump all air overboard until she warms up, or what?

 

LOL..... you guys kill me.

Ok, this weekend I am busy, but Monday I will swap out my throttle body for a different one I have here. Get back to ya!
Thanks,
Chris

 

my 3000-3500 idle doesnt stay for 17 seconds, more like 6or 7 is that normal?

 

I wouldn't think so, but then again 17 seconds seems like a long time while she's doing her thing too

 

Ok,,,,,, the chamber leading into the thermowax pellet was clogged. As well, the gasket had so much build upon it, it was also clogging the water passage. I tested the pellet, and it works fine. I will start it at lunch and see if the idle drops.
Thanks,
Chris