ok , I have a 90 jeep 4.2L 5spd Islander: I will give you the short form but know that i have been screwing with this POS for over a month and can't get it to run right. I have installed a new AX15 tranny, new universal joints, motor mounts, new carter BBD, new exhaust manifold and both gaskets, new harmonic balancer, coil, plug wires, plugs, dizzy, cap and button, I have eliminated all unneccesary vac lines, and nuttered it. Whew! Ok here is my problem: I cannot get it to run right. I have read all the varying opinions on setting timing and car set up and carb adjustment. I have all new vac lines on the ones I left. I have tried every and I mean every different setup on timing/carb adjustment. The damn thing still runs rough, and acts like it aint getting enough fuel through the carb or something. the only way it will run is with the vac advance disconnected and capped. otherwise it back fires so bad the cops have been called out three times this week, because my nieghbors thought someone had been shot. along the way I have had it running real good, until the test drive, and had issues which kept me from driving it. as of right now i am at 8* BTDC and idling around 1100 rpms. any lower and it act like it wants to die. It runs like it is on 3 cyl, and it misses . I have followed all the steps step by step and seem to be the only one having this issue. Oh i am running the stepper set 1/8" from carb wall with the SM disconnected. I am lost and very tired of working on this jeep without results. Can anyone help me? I am at my wits end.