I've owned my 90 Firebird for a few years now, and it seems every fews months that my car get 1 injectors that seems to become dirty (and whenever I step on the gas I get the spit and shudder due to the lack of power). Is there any way to pin point what is causing this to happen over and over again. IIRC my pump does have the dreaded wine.

First time I encountered this problem I thought it was the injector that went bad, so I bought one from Advance (I didn't last but a few months until it went out due to being faulty), so I had purchased a new set of 6 for around 200$ hoping it would fix the problem.

Every maybe 2-3 months one of my injectors (not necessarily the same one) gets dirty from the fuel side (not the nozzle). The screens catch the debris and I merely clean it off. Any suggestions on how to find the culprit?

 

Dirty fuel tank

 

Rev flush the whole system, a section at a time, then change filter from sock on pump to front.