Hi guys

Got a major problem with my car

I got a 1993 fiesta Cayman . It was given to me as a project , I've got it back on the road but this thing guzzzles petrol. £20 of fuel does about 40 miles Surely this can't be right ?

So far I've done a service , with plugs and filters and changed thermostat but no change

It's running very rich . In the morning when starting its chucks out a black substance on the floor And judders before moving off ...

Can anyone out there please help ? Apart from this problem it's a great car with only 50k on the clock