My dad has a 1999 suburban , 125k miles , new pmd with resister , Holley blue lift pump , smokes alot on cold start up and runs rough , runs great when warm , brand new injectors just installed and didn't fix the issue .. any ideas ? Thank u

 

you may need to advance the timing a little.

 

Too many bad glow plugs I expect

 

That would be my assessment as well check glow system, OP said smokes then clears when warm, white smoke smelling like fuel ?

 

Yep, my dad's old farm truck (also 1999) GMC 2500 did the same thing with the smoke show, and exact symptomology. We changed the glow plugs, and relay (just because), and that fixed the issue.....no more smoke show. Ran smooth when cold (albeit noisey) and even better when warm.

 

You haven't seen smoke till you crank one up at -20 or colder ,and talk about noisy !!!