ok here we go. 1993 xj 4 door 4.0 ho . 190,000 miles on her. i dont know alot of her history. ok she threw #1 rod out of the block ( my bad ). my family buisness is a machine shop for rebuilding engines ( not installing ) . we built a new 4.0 with a little extra pep to it just in the head & block. before we pulled the motor i could still start & drive the wounded girl. now with a fresh motor she ran for 15 seconds & ran crappy rough, then she died. we have changed the crank sensor, the ignition switch ( on the steering colum ) , tested all of the relays ( that we could find).
she has spark & awesome fuel pressure. when we put on a timing light it didnt flash bright enough to hardly see & it flashed REALLY slow. pulled the distibutor & retimed the engine. no good & still wierd timing light.
going to check the ecu next.
any ideas? <img src="/forums/images/graemlins/scared.gif" alt="" />

YAY!!!!!!!!!!!!!! ecu fixed it!!!! had a ground wire hooked to a positive & it fried the ecu. so now i have my 4.7 stroker ready to rock out!!!! <img src="/forums/images/graemlins/butwiggle.gif" alt="" />