high fuel consumption

[mutt1960]

hi can anyone help me with this problem, i have a 2.1 inj 1990 van when i rev my van black smoke comes out the exhaust it is only doing 14 miles to the gallon and thats on a long run .probably doing less on a short run, any ideas what the problem might be.the garage that i took it to did something with the air flow mixture but its not fixed the problem might have even made it worse. any

[mrhutch]

what engine code?

[Bigfootedboarder]

Air leak, metering unit faulty?

[mutt1960]

what engine code?

dj