brent4kQuattro

Ok...just wondering. My 4kq continues to run poor until warmed up. I thought it was running rich...but now I don't know anymore. Thought I would check the cold start valve. Pulled it out and had someone start the car while i plugged the hole...it sprayed a tiny bit of fuel...could hardly see it. It's not leaking at least. Waited a few minutes and tried again...nothing. Pulled the coil wire off and cranked the car for 10 seconds...no spray. Left it, came back in 10 minutes and tried...no spray while the car was running...or while it was cranking with the coil wire off. Is this right? Is there something wrong with the Thermotime switch...and does any one know where that is located? Do neither of these have anything to do with my poor cold running or should I be looking at something else?
The frustration continues...

85-4kq-girl

Lots of good talk about cold start sensors, thermo time switches, locations, etc. Hope it helps?

--morgan<ul><li><a href="https://forums.audiworld.com/4000/msgs/47951.phtml">Click me!</a></li></ul>

austinado16

The thermo-time switch is the big "sensor" looking item that's screwed into the coolant flange on the head. It has a big tall brass hex base for putting wrench on. Real big. It only activates the cold start valve during cold cranking and only when the starter is cranking. Since it is sensative to coolant temp and power from the key, it shortens the spray time of the cold start valve each time you crank....so as not to flood the engine.

So, first thing cold, you should get a good few seconds of cone shaped spray from the cold start injector. After that, the time duration of the spray will shorten.

If you have cold running issues, you need to be looking at the items I listed in your other post and resolve them.