I'm trying to turn off the CEL on my 95 Ranger. Getting a 1443 code-purge valve open. My purge valve seems to be stuck closed. It holds about 25" vacuum and won't release with the key on. There is another relay (dealer called it a thermistor) in the system. The hose comes from the manifold to the thermistor, to the purge valve, to the charcoal canister. All I can think is that it must be some sort of voltage regulator that varies a valve with temperature. Anybody know? The Haynes manual doesn't say anything about it. Thanks for any help. I ordered both parts from the dealer and will change them soon, but really am curious.

 

Maybe this thread from the FTE 3.0L V6 Forum will help you out a little:


Evaporative Emissions Control Valve (EVAP)

 

Thanks Rockledge. That is the same system I have. But I am still wondering what it is? What does it do? From what I have done so far I think my problem is the purge valve. But for $25, I figured I would change it too, whatever it is.

 

A thermister is a Thermal Resistor. It's a resistor that has different amounts of resistance based on the temperature. For example, the IAT is a thermistor, when cooler air comes into the intake it has higher resistance and when the intake air is hotter then the resistance is lower.

 

Lone Ranger hit it right on the nose.