7.3 PS hard start and rough runing

[prepowerstroke]

hey guys my dad has a 2001 7.3 powerstroke and it is a bear to start even at 60 degrees! but we have replace the glow plug relay because the old one was burnt up. but now it is still really hard to start and when it does start it runs really bad misses knocks and shakes the truck.(i've read some people call it a popcorn maker) we are thinking injectors bad?? and sorry in advance if this is a stupid question im a IDI guy, i dont know alot about these powerstrokes.

 

[tbirdfiend281]

yes. unless he has a odII code reader, take it somewhere that can pull codes see if a code has been thrown for the miss. If there is no code for the miss the way to diagnosis it is a injector cut out test. You drop injectors in the truck, and watch the fuel supply pid, if the fuel supply ratting doesnt go down when a certain injector is droped, that means the injector is not contributing (as in misfiring)