Not an expert by any means but this may be simple, there was another thread here i think were the bolts on the Vibration dampener were to long and hitting the timing cover? A quick easy check Good Luck, hope its not to involved.
1987 YJ, 258, Weber 32/36, HEI, Custom Sound bar, Hardtop/Sun-rider/bikini tops, 2" Lift, 1/2" Boomerangs, 1" Body & MM Lift. 32x11.5x15 Copper STT's on Black Rock 950 Lobos w/4" backspacing, Still need Front Bumper and Seats.
My build thread: [url]http://www.jeepforum.com/forum/f12/my-very-slow-87-yj-build-thread-1137667/[/url]