electrical problem!!!

well on a mission to replace my motor mounts on my 89 xj 4.0 i found i had to remove the oil filter. So after discovering my oil filter being abnormally tight and trying everything to get it off we decided to try to use some pliers. well the end of the pliers hit something and sparks flew. so i immediately tried to start it to see if it blew something. So it cranked over fine, but as soon as the rpms start to drop to normal idle speed it shuts off.. it doesnt sputter it just turns off. so the first thing i tried was i moved the 4 relays in the ecu around to see if maybe i blew one of those and that didnt resolve anything. I didnt seee any blown fuses either. so what do you guys think. and i also didnt notice the fuel pump prime like it always does. but the jeep is turning over for a few seconds so i dont think its starving for fuel. my jeep did this before after we replaced the head gasket we forgot to plug the map sensor in and it did the same exact thing.. but this time i dont think it has anything to do with the map sensor. thanks guys

The spark you saw was probably when you touched the 12V positive lead to ground which goes to the starter solenoid.
Check all the fuses; you probably find one is blown.

All fuses under the dash were ok... could I have maybe damaged the solenoid? But then again if I did it probably wouldn't start like it does...

Sparks down by the starter or up front by the alternator?

There are fusible links on the wires that run off the starter relay's large lug--the Renix PDC.

If you aren't getting a prime at the fuel pump the B Latch relay is suspect. When you turn the key to ON the ignition switch provides 12 volts to the relays, then if the ECU does not get a signal from the crank sensor it cuts the grounds for the relays.

Note: as you have just learned, it is good practice to disconnect the negative battery cable before doing most work on a vehicle. Unless you need the engine running or need a particular circuit "live" disconnecting the battery will save you a lot of misery.

Well the sparks were near the back left of the ac compressor.. that's about how I can explain where it was. Now the b latch relay is one of the four relays on the ecu on the passenger side fenderwell correct? I've had problems with then before luckily all the relays on my other parts jeep were still good because vato zone said they couldn't even order them. I haven't checked napa I'm sure they will be able to. I hope its not a dealership only part!

Those relays are literally a dime-a-dozen at salvage yards around here, and they are a simple relay most COMPETENT parts counter monkeys can find for you.

Ok, just for terminology sake: the Renix ECU--engine control unit--is inside the passenger compartment under the dash on the driver's side, around where your right knee hangs out.

There is no PDC--power distribution center--like the 91+ have. There is the starter relay and its one large lug. Those wires that attach to that large lug have fusible links in them, test them for open circuits as that is likely where the sparks flew from. Use a bright light, generally you can find the burn marks where the bare metal contact was made.

You need to take your time and check/test things, but I would start with the starter relay and the fusible links.