i went out 2 start my truck the other night and it cranks over fine but wont start.

i cracked off a all the injectors 1 by 1 and made sure there was no air in the line
i then pulled out each glow plug and hooked them up to the battery and they where fine
batt voltage is good and i can hear the glow plug relay click over
question is what do i check next? and have i missed something?

any help would be appreciated cheers
