So i was on my way to work then out of nowhere, with no warning my xj just shut off and would not start back up. after towing it home i tried starting it again still no go just kept cranking. a few hours later came back went to go start and VIOLA it fired and running really ruff as if it were running out of gas, sputtering, stuttering etc. Had to keep playing with my gas peddle to keep it running. Now i did the first few simple checks, did i have gas? yes i had a full tank, I just rebuilt this engine about a month ago in the rebuild i replaced the TPS, IAC, BRAND NEW distributor, New crank position sensor, three new PCMs, New timing chain along with having it timed correctly via chain that is. I replaced all fuel injectors and new fuel filter along with new fuel pump replaced before the engine rebuild. Now all i know is that i was shooting of codes telling me that i had a cylinder 1 misfire and then random multiple. After the incident it gave off more codes. Cylinder 1,2,3,4 are misfiring with multiple random misfires..... and coolant temp sensor is high voltage. one more piece of info is i had the timing for the distributor advanced a little, causing my xj to run very rich don't know what this has to do with anything but with vehicles it could be anything. Please help i'm at a loss.