hello everyone, I have a 96 XJ6 an d when I go to start my car, not everytime but mostly I get that rough start and a shake, sometimes its smooth, espically when I fill up my gas it starts smooth, and then later on it has the rough start. I just installed a new fuel filter a week ago, and as well did a fuel injector cleanup by pouring lucas into the tank but still hasent caused the problem to go away, does anyone know anything, thanks......

 

Maybe the thermostat for the ECU. Should be pretty cheap. Perhaps you're running lean because the computer thinks the car is already warmed up to operating temp. It's an inexpensive guess.