Can using biodiesel cause your glow plugs to burn out early? I have a 99 PSD turbo. I am having starting problems. I have to cycle the Glow plugs about 5-6 times before it will start. I checked the glow plug relay control by the fuel separator and it is good. cycle's just like it should. If I plug the pick up in, it starts right away. How many of the glow plugs have to be bad before it does what mine is doing?