1991 B2600I Questions

Recently bought my second B series. First was a 92 B2200. Now, a 91 B2600I. Much better power. Fuel meter does not work. Ideas? Also, I would like to improve my gas mileage. Would a cold air intake improve the mileage? Where can I buy one? This is a clean little truck. Garage kept and a one owner. Everything works except the gas guage. Thanks for the help!

9 times out of ten, the sending unit is the culprit located inside the tank but to verfiy I will usually check a book for resistance values and then you can go down to radio shack and buy some 1,2,5,10,50 ohms resisters(depending on what ohms you are trying to achieve) and put them in line with the harness and see if your dash gauge working properly. Good luck.