Nissan Repair: excessive fuel usage, fuel milage, vacuum leak

Question
Hi , I have a 1986.5 D21 hardbody pick up w/ 4cyl TB injection 5speed man trans. My fuel milage has gone bad, I can't adjust my fast idle control device and when I look into the TB its spraying way to much fuel. It was idling fine but to day it would not stay idling. Do I need a new set of injectors or is it something else?

Answer
Patrick,

First, check the computer for codes.  If the throttle body injectors are spraying too much fuel and the idle is excessive and the mileage is down that means that there is a vacuum leak and the computer is compensating.  I would check for computer codes first, then the fuel pressure, and for vacuum leak's in this order