89 xj acting weird

first off I have an 89 xj 4.0 4x4. I rolled it over a few months ago and then chopped the roof and just got done building a custom roll cage on it.

I drove it home from the rollover and it drove just fine 70 down the highway. Its been starting and running fine for the last few months too in and out of my shop.

I was going to take it out wheeling yesterday when I started it, it idled for about 10 minutes no problems. as soon as I hit the gas it died... and refused to start again, it acted like it wasn't getting fuel but the pump is kicking on still (you can hear it) I added a couple gallons of gas and it started again. drove it out there and it spat and sputtered the entire way but never died.

I wheeled the whole day and it didn't cut out or die once... driving back that night it died again and this time refused to start at all.

I had a friend tow me back but while hooking the strap up I had no dash lights or brake/rear running light. However the headlights worked just fine. then to top it off when I would hit the breaks the dash and brake lights would flash on but if I let go of the break the dash lights would shut off again.

Im thinking I have an electrical issue but im just not sure what it could be or really where to start digging. Any ideas??

Sounds like a ground issue. Refresh or replace ground cable, cable on drivers side firewall, and ground wires at base of the oil dipstick. Also check the ground wire under the dash on the drivers side near emergency brake pedal.

ill take a look at them this weekend and see if it fixes it

could also be damage to the ecu from welding
did you unhook both battery cables?

No the battery was not disconnected. I didn't even think about that. But the welding was done over a period of 5-6 weekends and each weekend it stared right up no issues. If it was a ecu problem I don't think It would run right all day while I was wheeling. But I could be wrong, I don't have experience in electrical issues. I'll check all the grounds this weekend and see if anything is loose or dirty. Is there anyway to check the ecu?