i have an 1985 720 4x4 with the z24 carburated motor in it, earlier this year it started to sputter in 1st and second from 1k rpms to 3k rpms but only when it is cold, on top of that my fuel mileage dropped to about 10mpg, ive had the carb rebuilt, replaced the o2 sensor, coolant temp sensor, fuel pump, and exhaust manifold. The sputtering isnt as aggressive as it was but it still does it and my mpg is still garbage. ive done done plugs and wires and ignition coils as well and it didnt seem to change anything. it was able to pass smog on its own and better than most modern cars. im tired of dealing with its morning bitchiness and would love any guidance on to what could be causing my truck to be a twat. p.s it does have a a rebuilt motor in it along with head work done to it all before i got it, the motor has about 60k miles on it currently.