Kodfish

iTrader: (1)

When does the ecm tell the canister purge solenoid to open? I pulled the solenoid off the canister and watch the opening from the bottom to see if the valve would open and it never did. Engine was idling and at normal operation temps. Does the ecm have to has a vss signal to open the valve? When taking a ohm meter to it, the ground wire to the ecm reads 23kohms to 15Mohms. The voltage is good on the power wire but I do have a question about that. Are the volts suppose to rise any during engine operation? With key in run, volts are 12vdc. While letting the engine run, the volts seemed to rise to 14vdc. Again does the car has to be in motion to get the valve to open. I tested the valve inside with a ac/dc adapter; put 12vdc to it and the ground and it opens. Just doesn't work in the car? Can someone let me know how this thing works. Thanks a bunch.

I H8 WWD

iTrader: (5)

This may help.

Direct Link, scroll about 3/8 down
http://imperialclub.com/Repair/Fuel/overview.htm

You'll find this.


The PCM energizes the canister purge solenoid and allows vacuum to purge vapors from the canister under these conditions:

1. 150 seconds have elapsed since the PCM entered closed loop.
2. Coolant temperature is above 176 degrees F. (80 degrees C.).
3. When the PCM is not enabling injector shut-off, such as on vehicles with traction control while one drive wheel is spinning.
4. The idle contact switch in the IAC motor is open.
5. Vehicle speed is above 20 mph.
6. Engine speed is above 1,100 rpm.
7. The engine metal temperature sensor is not indicating excessive temperature.
8. Low coolant level is not indicated.

If any of these conditions are not present, the PCM does not energize the canister purge solenoid, and the gasoline vapors from the fuel tank are stored in the canister.
When the engine is running, intake manifold vacuum is supplied to the TPCV valve. This vacuum opens the valve and allows vapors to flow through the valve into the canister. When the engine is not running, the TPCV valve closes, and fuel vapors are contained in the fuel tank. If the tank pressure exceeds 15 inches of water with the engine not running, this pressure forces the TPCV valve open and allows vapor flow to the canister. The canister contains a liquid fuel trap that collects any liquid fuel entering the canister. Condensed fuel vapor forms liquid fuel. This liquid is returned from the canister to the tank when a vacuum is present in the tank. This liquid fuel trap prevents liquid fuel from contaminating the charcoal in the canister. The EVAP system reduces the escape of HC evaporative emissions from the gasoline tank to the atmosphere.

Kodfish

iTrader: (1)

Thanks for the info. I thought the vss signal had to be present. My tank control valve is bad/destroyed and have to get an new one.

Ahmed Hassan

what if the purge canister valve is open all time like when then engine is cooled and operate on open loop and temp below 70C?