[TL Acura 98]

SMOG SPECIALISTS please comment

How does the 98 TL create pressure in the gas tank without a pump in the system?

98 TL shows check engine light - error reads problem with evap system.
Have put smog in the system, can't find a leak anywhere.
We use computer to turn on and off every sensor in evap system one by one, everything is working great.
Gas tank won't pressurize=check engine light=can't pass smog

Suggestions appreciated. The car has been bulletproof, literally gas and oil only.
OK tires, brake pads, flush radiator fluid and timing belt (@180K mi now) but still bulletproof in my book.

Thanks,

 

[Hondacuraplanet]

The whole purpose of the evap system is to minimize the amount of fuel vapor escaping to the atmosphere. You don't need a pump to do that.

EVAP control canister purging is done by drawing fresh air through the control canister and into a port on the throttle body. The purging vacuum is controlled by the evap purge control solenoid valve.

When fuel vapor pressure in the fuel tank is higher than the set value of the evap two way valve, the valve opens and regulates the flow of fuel vapor to the evap control canister.

So there's the theory, let's get down to business . What is the actual code being thrown?