Re: Thermo Time Switch

[Russ Maki <rinard@execpc.com>]

Russ Maki wrote:
> 
> Fourkguy@aol.com wrote:
> >
> > Any BTDT on R&R of Thermo Time Switch - 86 4KCSQ.
> >
> > Trying to get rid of my cold start problem. Swapped CSV with my 4K with no
> > change. Think it's the thermo time switch. Is that the one at the rear of the
> > head on the I5. The 4K mounts it in a coolant line - right?
> >
> > Can I just pull the TTS plug and jumper the terminals to test CSV function?
> >
> > Thanks for any suggestions,
> >
> > Jeff
> 
 Hallelujah. I just solved this problem on my car half an hour ago.
 The car started fine til my mechanic adjusted fuel mixture back to
specs...then it began stalling out when cold. But my gas mileage has
improved!
 I pulled the connection to the cold start valve, hooked it up to my
 voltmeter and fired up the starter...the 11+ volts that are supposed to
 be there with the starter turning were nowhere to be found. So I pulled
the connection to the thermo time switch (yes, at the back of the head),
ran the V-meter between the hot line and
 ground, fired up the starter and found the voltage strong at that
point. Voila...in goes a new thermo-time switch. Better results but
still not right.
 Checking the temperature sensor with an ohmmeter, I found resistance
was absurdly low...the car probably thought it was on Venus. It's
supposed to read 2.5K ohms at 68 degrees F; my bad switch read about
one-tenth of that (resistance drops as temperature rises). 
As a test, I jumped the temp sensor plug through an old spark plug
resistor wire (go ahead, laugh) and the cold start stalling abated. So I
dropped in a new temp sensor -- problem solved!
By the way, the temp sensor is about half as expensive as the
thermo-time switch, so you might want to check that first!
Russ Maki