There is a vast amount of resources on and off the net that will teach you the ins and outs of the factory set up. If your carb is truely worn out, refurbished units are available. For the cost of adding Fuel injection to an existing engine (ie the 4.2), why not exchange the whole engine/induction combo from a donor vehicle like a low milage,new, but wrecked/flipped Cherokee. Just a thought.
1975 CJ-6 304 T15 Dana20 30/44 3.73
1983 CJ-8 258 T5 300 30/44 3.31 Looking for full or half hardtop buy or trade
1986 CJ-7 Laredo 4.6 stroker T5 300 30/44 3.31
1986 TJ-7 Trail Jeep project in the works
2003 Inca Gold TJ Rubicon