Hello everyone. Dealing with a 2002 Chevy blazer with a stutter and stalling issue during warm up. Trying to find out when the Evap purge valve should be supplied voltage. Upon startup it gets battery voltage when cold. Trying to figure out if that is normal. Thanks!

 

Probably doing a leak test. This is something that PCM chooses to do when the engine is cold. See description and running the DTC in the attachment for P0440 (note coolant temp reqirement). If no code, then yours is passing the leak test in any case and it appears that purge valve is working.

 

The charcoal canister was absolutely soaked in gasoline. Thinking that’s my problem!

 

During engine running the evap valve is almost always open and the purge valve throttles but is almost always at least partially open. Except as Les says, during a leak test. A gas soaked canister is usually related to topping off at the gas station.

George

 

Absolutely. I’m guessing the previous owner topped it off frequently. There was gas on the Evap purge solenoid!