lambda question

[Delorean17@xxxx]

Hello list,
I finally got my engine back together after replacing the water pump 
hoses and gaskets. My car has always ran rich since I bought it(only 15 
miles ago) 
It smells like gas real bad when it runs and you can see a little smoke 
coming from the exhaust. I tried tuning the 02 mixture screw back about 1/8 
turn but then the car will begin to stall out so I have to turn it back in to 
keep it going. It has a brand new 02 sensor. The frequency valve runs 
constantly and never shuts off. I think this may be part of my problem. It 
used to shut off or slow down after the car heated up but now it doesnt. 
someone suggested that my Lambda ECU is bad. how can I test it? I checked 
the Lambda relay and it is not stuck, its working fine. any help would be 
greatly appreciated!

Thank you
David
#2496-