I have 3.55's and I just pulled the IAT and MAP they both were fairly clean. I checked the oil and I cant tell any traces of fuel. What else could it be

 

Fill her up, go down the free way for 30 miles with cruise set to 60 mph, 65 if 60 is unsafe, and fill up right when you pull off the freeway. Be sure to fill to the same level, filler neck return vent hole works good for reference. Divide miles driven by gallons and report back.

Do you have bigger than stock 245/75/16 tires? If so, has your speedo been adjusted? You odometer runs the speedo so if your tires are not stock, your odometer will read slow. About 3% for 265's, 6.6% for 285's, 11% for 35's/315's. If you are getting 12mpg with 315's and an incorrect odometer, that will equate to 13.3 or so mpg. This could be half of the problem, the other half being a brick foot.

 

try what ^^^he^^^ said, it sounds pritty simple to me if ur hotroding around most people see around 13 or so, if ur trans is slipping, then tak a mile or 2 off that and u got ur 11, keep ur foot out of it rpms below 2k and i bet ull be doing great. my tc is shot so im seeing about the same as u around town, but hit the freeway and im over 20

 

Only the early models had 3.07s with 3spd trannys, the later ones had 3.55s with 4spd trannys(no lockup). I got about 16mpg on my modded '92 pretty consistently with my heavy foot.

My '01 ins modded similar to yours and I get 12-16mpg depending on temp and how I drive. I usually drive heavy footed with Juice set on 4. If I set it to 2 and ease up a bit I can easily pickup 2-3mpg. More if I keep the speed under 65mph.

Your aggressive driving, slipping tranny and the fact that we are still in winter blend fuel more than explains your 12mpg.