Bad injectors or Bad pump causing knock?

[my_gst95]

I logged my car one night and notcied that it started knocking (aprx 10 counts) at only 14 psi. Not thinking much of it, I later put 100 octane and was tuning with no sign of problems (0 counts, perfect timing at 19psi of boost). Later, I put 91 octane back in for daily use and now it seems even worse (17 counts of knock). I had to put my safc close to +18 just to keep my timing where it needs to be. And I know it has to do something with my fuel delivery system because my O2 #'s are lower then ever before (usually they are .89-.87, now they are .83). Is there any way to test out my injectors or pump to see which it would be? I even tried changing out my fuel filter to a standard new Fram, and it didn't help at all.

90GSX
255lph (not rewired yet)
stock 450cc
s-afc
tuned with MMCD software


Will the IPW tell me anything (ie if the injectors aren't spitting enough fuel?).

my_gst95

 

[btrux06]

can u monitor pulse width of the injectors in form off 0 to 100 percent duty cycle to tell if your maxing out the injectors? that or bad fuel pump could be possible, i had a bad pump once and testied the fp from the tank to find the problem

 

[my_gst95]

Thanks for the reply. Injector duty cycle looks pretty smooth. It floats around 62% at 4500rpms and ends at 96% at 6800rpm. Getting some 550's may help so I'll have to wait and see. How did you test your fuel pump, just by a voltemeter? If I buy the B&M Fuelpressure gauge that sits on the filter, would that be a good indication if my old 255 is bad if I'm not getting my base pressure?

thanks,

my_gst95