contact Marren fuel injection (injector.com). I had injector issues that blew a motor. I sent all 16 of them to him marking them as port/starboard and cylinders 1-8 so he could clean/test them. He called me back and told me which 2 pistons I burnt holes in after testing them. He sells new ones cheap too if you need replacements.

well i tried my idea of testing the fuel injectors while in the rail but lifted out of manifold and it didnt go so well, when i primed the rail with fuel it just pushed a few injectors out a little dumping the gas out. so now i cleaned them up and im gonna send them out to be balanced and flowed at cruzin performance.
i also cleaned the throttle body and iac. i see that the iac is spring loaded but when i push on it it only moves very little and wanted to know if that was normal?

ok heres an update, i cleaned out the injectors, iac valve, throttle body and the air cleaner, reinstalled everything and checked fuel pressure again.
key on engine off had 34lbs but started to drop right after pump stop and got to 0lbs after 3-4 mins.
engine running had a steady 34lbs also.
removing the vacuum lines from the pressure regulators showed no increase or decrease in fuel pressure, i removed one at a time for both tests.
the engine was running on the hose and when i revved it up the pressure stayed at 34lbs.
the good news is that the hiss from the iac pretty much went away and i wasnt having the surging problem like before.
so do i have a fuel pump problem or fuel regulator problem?
i have a low pressure pump feeding the high pressure pump but the inline gauge i install after pump before water separator shows only 1 to 3lbs of pressure when running....doesnt make sense to me...sometimes it shows 0lbs when running....

here is how my fuel set up goes from tank to low pressure pump which is mounted 1" below top off tank, into the water separator, out to the high pressure fuel pump on the fuel cooler, from fuel cooler it goes to the fuel rail in, and the fuel cooler regulator return line goes back to the water separator. from the fuel rail i also have a return line that goes back to the gas tank. when the engine is running there is alot of fuel being returned through this line and the more throttle i give the faster the return line flows back to the tank.
am i losing to much fuel pressure due to having 2 return lines ?
is one or both of the regulators bad?
whats my next step i should be trying?
really need some help with this one......

sounds like the fpr is not holding its pressure, seems they are cheeper then a fuel pump and thats what i would replace first..

Multi Port injection

which regulator should i change? the fuel cooler one or the one on the fuel rail?
i have the green circle on my cool fuel regulator...is that the right one or do i need a different color/marking one?

did you ever ohm your injectors with key on?