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Repeated po446 issue
Another shop replaced purge valve and vent valve with filter
I tested both these parts with smoke machine they test normal and function when commanded by scan tool
Smoke tested tank with through vent hose connection it holds, and pressure transducer increases as tank fills with smoke. removing smoke machine from tank with vent hose open there is a slow decay of pressure sensor reading down to 1.45v. I can physically blow in vent hose with cap off and it is restricted, don't know if that's normal or not. It fails service bay test of evap system
I'm suspecting a restricted canister. I cannot find info on how open the vent line from tank to canister vent valve should be normally
Ideas on checkout would be appreciatted
Guy
Fuel Tank Pressure Sensor... voltage at no vacuum or pressure should be 1.5v. Lower voltage equals high vacuum/pressure. You're at 1.45v so sensor is registering vacuum/pressure. Run the car, command the purge to 50% with the vent command closed. Watch the fuel tank pressure mmhg and fuel tank pressure voltage. Voltage should increase and vacuum decrease. Stop the purge command keep vent closed. Open gas cap, should hear vacuum escape. FTP voltage should drop to 1.5v and FTP mmhg should drop near 0.
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