I have an 89' Pioneer 4x4 with 4.0 and AX15. I just picked the truck up in July and have been going through it to make it a reliable daily driver. It has just over 100k on it and I knew the original owner. It was parked 5 years ago because it was running sluggish and rough. When I got it the fuel pump was not working so I dropped the tank and replaced the pump / found the tank was rusted and replaced it. I swapped over to 4 hole injectors and put a new fuel regulator in along with all new fuel line connectors etc. I also did Cruiser's upgrades (cleaned connectors, new power and ground wires, went through the fuse box etc). The truck runs great and starts up instantly. However when the truck is warming up it will randomly shut off or go to 100-200 RPMS when you push in the clutch after you have been driving down the road. If I drive the truck and let the clutch catch and gear it down that way the issue is never there. Once she is warm I do not seem to have this issue. Also, my idle is slightly high at ~900 RPM. I have been through crank case lines and all vac lines I can replace, next is TB gasket and cleaning. I have not checked the TPS yet if that helps.
