My 1990 s10 blazer 3.4 won't start when cold. I have to use starting fluid. It starts fine when it's warm but it surges when it idles and drives. I replaced the TBI the fuel pump and also looked for vacuum leaks and found non. I need some fresh ideas it is my only means of transportation, so any advise would help.

 

check the egr valve. Injector spray pattern, and an actual fuel pressure test would be nice. Its a 4.3 not a 3.4 right?

 

that,and hopefully you didnt install a cheap pump,these blazers cant stand em.

 

What brand pump did you put in?