A real mind boggler

Hey guys i have 1991 Ford Explorer standard 5 sp 4x4 sport and i dont know whats going on i seem to be losing fuel faster than i can put in, No that is a bit extreme but have a gone 87 km on about a little better than 20 litters and it went to the shop once already without a computer test and the mechanic just changed the spark plug wire that seemed to work, till i filled it up and now here i am 87 km's down the road and 20 liters of fuel gone...please help

Hi, RE Your exploder fuel consumption problem, Any codes?, If not, Take the vac, hose off of the fuel pressure regulator, Any fuel?, Smell like fuel?, If so replace the regulator,. GOOD LUCK...Clay..