1996 jAGUAR XJ 6 4.0 liter. Very hard to start, cranks for a long time before starting. When it fires up it suddenly stalls out. Try starting again, cranks and cranks, if it does start and let it run for 10 minutes, turn it off, when starting aging cranks and cranks. Is this the fuel regulator or an elctronic part next to the fuel regulator. HELP!