1987 Scottsdale 4.3l TBI question and concerns.

[JustAGoodOleBoy]

So I have a few questions and concerns about my 1987 Chevy Scottsdale with the 4.3l tbi engine.
I drive this to work everyday and its been pretty reliable for the most part.

I know its a small engine for a truck this heavy, but it seems I get pretty crappy mpg even though most of its driving is back roads or freeway. I also am wondering why I can only fill up to just under a half tank on either 20 gallon tank.

Anyways, I've noticed my Air filter gets quite dirty and smelling strongly of gas in no time at all after being replaced. That isn't normal is it?
I get hesitation sometimes when accelerating. When starting up to go to work it seems it will dang near die

If anyone can give me some insight that would be awesome

[Captkaos]

without more information I would suspect that the TBI needs rebuilding or the motor needs some attention.
As for the aircleaner it should not smell like gas.  Are you saying it gets dirty immediatly or over time?  Is it open to the air?

[Dr_Snooz]

I'm wondering if there is a rich running condition combined with a lot of blowby, being dragged back into the air filter by the PCV system.