How many glowplugs can be bad and the truck still start? I got the plugs on the Passenger side changed tonight before it got dark. I only had one bad one on that side. I check them as I pull them out by hooking them directly to the battery with jumper cables. Now I have one better one than before and it still wouldn't start. I had replaced a bad one on this side last year as well and it started like a champ. I put a used one in though, that's why I'm just replacing them all with brand new this year. I'm wondering how many I will find bad on the driver's side tomorrow. I would guess all of them. Also, can anyone tell me the torque on the plugs?