Car misfire and Activated charcoal filter

[bryan grayson]

I have an 1994 audi 80 sport that seems to misfire when you lift off the accelerator.

I have tried all the obvious normal tuning checks and replaced most things (plugs,leads distributor caps ect) including the airflow sensor and had tuning by race garages but they can not find the fault.

I am now getting the occasional fuel smell and was wondering if the activated charcoal filter and solenoid could cause this problem.

Any thoughts would be appreciated 

Rgs

Bryan