91armygreenXJ

as some of you may know, i did an engine swap on my 1991 xj. i got an engine that i know 110% ran when pulled out of a 1993 xj. everything is wired up correctly. i still have no fuel/no spark. the jeep is giving and recieving power from the crank sensor. the jeep will crank over forever but will not fire up. keep in mind the jeep has a brad new crank position sensor, coil, and complete distributor. would the ECM being from a 1991 mean anything? i have the ECM that came out the the jeep in which the motor was pulled. i have brand new cap, brand new rotor also. i am getting power to the coil but not after. please if you have any questions about this before you give an answer i will be happy to answer them. if anyone could shed some light on this it would be GREATLY apprieciated.

That Jeep Guy XJMJ

first off (if you haven't already) try your other ECM, also before pluggin it in, take the positive end of your battery cables and after removing it from the positive side of the battery touch and hold it to the negative side for a few seconds, (this will drain any power still in your harness in the ECM or other areas).... then plug in your "new" ecm and before starting it up cycle the keys a few times....

also i gotta point it out.... if you have power going to your Coil but not out.... then wouldn't that obviously mean your coil is bad.... I know you said its Brand New but it still could be the one that came from the parts store defective... maybe another coil and check for the same symptoms...

I have in the passed has an issue with my wire harness in the whole Coil/alternator/starter area, i figured it out by wiggling it around while my buddy was turning it over... Spark and runs then cut outs then sparks and runs again

hope this helps, keep us updated

91armygreenXJ

I tested my new coil on my dvom after looking up specs for it and it seemed alright. I thought the same thing. But if its not raining here tomorrow im definately gonna swap the computer. The thing is though if i put a different computer in wont i have to get it programmed before i can start it? Or will it run without that?

That Jeep Guy XJMJ

i've never had any of mine re-programmed or flashed before i swapped them and
a few of my buddies have done a couple... (like 5) NOT a whole bunch.. but each time we swapped them we always "drained" the power in the harness "system". It all worked out each time, the key cycling acts like a booting process.. lets the computer power up and read out throughout your harness ya know meets and greets, gets to know the neighbors