If anyone who has any ideas on why I'm be getting poor fuel mileage please let me know.

I recently bought an 82 Chevy Luv w/ the Isuzu c223 in it, which is supposed to get ~32-36 mpg. I'm getting more like 20-22 mpg. I got 36 on my first tank, but don't know what has happened.

Could a clogged fuel filter do this? The filter was changed about 1000 miles ago. I don't suspect it, honestly, b/c I am not experiencing any other symptoms, such as poor starting or lack of power (although this little rig lacks power on its own).

I also put new shoes on the rear brakes and replaced both wheel cylinders. I'm wondering if somehow the shoes are not returning and causing drag on the drums. This would definitely cause poor fuel mileage! I checked for free spin after install though, so unless my old return springs are broken or bad . . .

Any ideas, especially if you've experienced this before, would be helpful.

Also, there seems to be a little bit more black smoke than there used to be, but I am not sure. I've only had this little rig for about 6 weeks.

Otherwise, it starts and runs fine. I do drive it easy, except for up hills, which require flooring it!

thanks,