I would start by getting it read for any codes.
(compression test, maybe?)
Normal RPM's?
Normal MPG'S?
I'm sure these guys here will be able to help you out more though. You're in the right place!! Most of the guys here know their stuff.
That being said, Igniters?=Injectors?
Igniters makes me think spark plugs.
REAL TRUCKS DON'T HAVE SPARKPLUGS!!
Good Luck!
chris