89 4.2 problem. Won't go over 50 mph.
My brother has a bit of a dilemma with his 89 4.2 YJ. Motor ran good. He had an occasional chattering sound which turned out to be the timing chain hitting the cover from time to time. Without any warning, the Jeep just died when he went to pull away from a light. Figured it was an ignition system problem, swapped modules, coils, etc.. Turned out to be the timing chain was so stretched he was able to lift it right off the sprockets, so it probably jumped a tooth (or two).
Changed the timing set, cap, cap base, rotor, plugs, wires, fuel filter. Got it all back together, took some time to get it tuned but eventually got it running smooth again. The coil wire was arcing, but that was fixed with the new wires.
It starts up, idles, drives just as it did before this problem, until you reach 50mph. It runs normal from 0-50, once it hits 51 it falls on its face. He can wind out 1st-3rd like usual. It's like it has a governor on it. Throttle linkage all good, carb is clean. Cat isn't clogged.
He has a Weber 32/36, nuttered, Team Rush mod with MSD 6AL, Ford coil, the plugs and wires are ones recommended in a thread by JEEPHAMMER.
Anybody have any ideas?