rough idle

hey guys well i have a 1990 b2600i and it idles rough exhaust smells bad sounds like its missing and iv done the following.
1 cap roater plugs wires
2 replaced intake gasket
3 replaced broken vacume hoses
it still runs like shit im getting fed up with it iv been through all the post and threads done most of what has been suggested already does anyone have any suggestions thanks

High fuel consumption?

yes very high

I've had this same problem twice before. It could possible be either the ecm or the crank angle sensor located under the distributor cap. It is black in color and half moon'sh shape. When they went bad for me it would be very hard to start and would smoke black when I accelerated. It was injecting way too much fuel. The spark plugs will probable be black if you checked them. I actually carry a spare one in my glove box. It is the thing with the 4 wire oval plug.

Mine would "chug" very hard

mine does the same thing when i back out of my driveway then take off i have a turn down on my exhaust it leaves a black line oon the road and my spark plugs are black when i check them iv changed them twice

Are you able to drive the pickup?. Both times it happened to me it was almost undrivable, at least I wouldn't want to.

i probably could if i tried but i really dont want to

Sounds just like that angle sensor to me. You used to be able to find them on ebay. But I just looked and cannot find one. If you take your distributor apart it will havew a "j" number on it...like "J315" or something. Or just by a different distrib. that will come with the sensor.

ok thanks alot man really thank you ill try that and ho[e it works