injector problems (code 27)?????? kinda long

Well the other day while driving, my jeep felt like the whole drivetrain just shut down and then came back to life.It ran fine for a while after that and then did it again a few days later.It shut off on me while coming to a red light and then started right back up.Friday it completely shut off and would not restart.I towed it home,checked and had no spark.I decided with 173k on it that it would be a good time to put a crank sensor in it. Well four days later and I now have a new crank sensor,new fuel pump,filter,pickup coil, tune up,and ignition coil.I still have this problem.I checked the codes and came up with a 27 which is according to my factory manual an "injector driver error".Well I swapped out a spare computer I have out of another cherokee and it started.I had no codes in this computer and it idled fine.I gave it a few taps on the throttle and it shut off again.It would turn over but no start.I have great spark and do have fuel to the injectors.I poured some fuel into the throttle body and it came to life till the fuel burned out and then died.So I guess I have an injector problem.My question is, is there a relay that sends power to the injectors?If the computer just grounds the injectors to fire them,then could I have a bad ground somewhere?I am at a loss and don't know where to go from here.I appreciate any help and would like to say this web site is awesome.I am new but will be around for a while.Thanks guys(and gals), Richie

What year XJ,You may be time and money ahead to have a shop or Dealer look at it.
You already have several hunderd $$ in it (depending on year) and are no closer to getting it to run.
Wayne

Sorry, it's a 93, auto, 4x4. I can't get it to the dealer because it won't start and at this point I don't have the money to let a shop look at it.My job title says I am a mechanic, but I am starting to wonder.I now feel like a parts changer! lol

Here is a link to a chiltons manual that I found while searching for cherokee links. It might give you a hand. I had the same problem with my 93, but the ignition coil fixed it.

Good luck.

http://www.cybrrpartspro.com/Chilton Manuals/9107m/9107.HTML