I have a 1999 XJ and it will no longer crank. The battery died so it sat for about a year. New battery and will not crank, it turns over, starter spins the engine, I can smell Gass in the exhaust, but will not fire. Before it sat it was cranking very ruff and running ruff randomly. I have changed the crank sensor, cam sensor, checked fuses& changed a couple relays just for good measure. Just is acting like no spark. Any help would be great.