I don't have the answer but I would suggest going to the manufacturers web site to see if you can find your answer.
No
20.3 gallons
about 7-13 mpg
it is mounted in the dash on the drivers side. It is designed to be see from out side the vehicle.
A few possibilities here. Oil and oil filter issues, fuel injector issues, cam issues.
It is possible for a 1989 Jeep to leak coolant from the surge tank if the vehicle is overheating. It is also possible that the surge tank has a crack in it.
It is located on the inside of the firewall, left of the steering column. It is way up and hard to see and get to, but it is there!
It is a mechanical fuel pump located on the engine. It is in the drivers side front below the distributor.
filter change low oil front pump
There is no switch to actually turn off the system, BUT, you might be able to beat it by NOT locking the doors with the door lock switch, but only lock them MANUALLY like pushing the slide to locked. . I know , but you can beat the system that way. Good luck
Remove the back seat fold back the carpet and there is a round access panel with four screws. the fuel sending unit has a locking ring holding it into place. be sure to thoroughly clean the area before removing the fuel lines and the locking ring. you can purchase a tool to remove the locking ring @ www.grandwagoneers.com. or you can use a screw driver and hammer as I did. This is NOT the best way. you then need to lift up and angle the sending unit to remove. Be fore replacing be sure to test the unit. this way if there is still a problem you are removing the sending unit again. Good luck
Go to your local Parts store and ask for a back flush kit and chemical flush. Follow the directions on each.