evap system on 2008 ve ss

[kimo.mq]

ca anyone please explaining me how the fully evap system work on the ve ss 2008 cause my ******* EVAP PURGE VALVE NOT OPEN AT ALL CONDITION OF CAR RUN (I HAVE A HIGH PRESSURE AT MY FUEL TANK I'M CHANGE THE CANESTER BOX ALSO CHANGE PURGE VALVE AND CHECK ALL VACUM AND PURGE LINES EVERYTHING IS GOOD BUT ECU WOULDN'T GET ANY REQUEST FOR PURGE VALVE TO OPEN (((ECU WASN'T KNOW ABOUT TANK PRESSURE))) i'm taking long and long time to solve this proplem I THINK EVERY BODY KNOW ABOUT HARDEST OF DROP THE PETROL TANK I'M DROP IT FOR MORE THAN 4 TIMES nobody know about this problem exactly i'm think that have an tank pressure sensor but it wasn't cause i was open the ecm harness for searching for fuel tank pressure sensor but the ecu have a plastic plug on the pin numper 24 on ECM,,, Please help me if any one have an exactly explain for that system and how the ecm know for the fuel tank pressure... thanks

 

[07GTS]

ecu dosnt know the tank pressure, if its excessive the cap should release some pressure, the evap is just used under curtain conditions like idle or cruse when there is enough vacuum on the engine, its just a emissions thing not a tank vent, just undo the the evap line at the tank/chassis join easy to do and let it vent, then block the evap solenoid so it dosnt allow air in and see what ever issue is fixed

 

[Fu Manchu]

Agreed. There’s no tank pressure sensor. It’s not there. The ECM will activate the purge solenoid when engine conditions suit it as mentioned above.

It’s a simple and effective set up. Fuel cap vents excess pressure.

There is a non return fuel system. Fuel only goes out.
The charcoal canister can be buggered but that’s rare.

There is a bunch of steps to take but I don’t have access to them at the moment. I’m sure someone can bump on the emissions pdf of it or the steps needed to check the system correctly.

From what you’ve written, it’s working fine.