[XanderWiFi]

Is this only on startup? I had a similar issue where there were no codes and it would start with a rough idle for a few moments then stall.

Turned out to be a poor fuel pump relay connection and eventually a new fuse box in the engine compartment. Find the relay and see if you can manipulate it to a better connection.

If it is something other than start up it probably is not something electrical as such.

EDIT: sorry I didn't read everything. Timing chain being jumped seems like a pretty good cause...Now that you know the problem compare prices at other shops and see who will cut you a deal.