I have been working on a 1987 lt4wd for the past year or so. My experience, the carb may be the issue. I rebuilt mine 4 times (moose parts), soaked, sprayed, everything. Finally broke down and bought a carb on eBay. Installed, started right up. Idle was uncontrollable. Replaced the throttle cable, runs perfectly now. Besides a slipping clutch! If you rebuilt the carb go back to the original parts, and check the cable for play. Good luck. Dan