well i have 24lb injectors,kirban fpr and stock fuel pump ! also when you rev it the pressure drops can't figure it out.... i wonder if the pump is weak ?
Not much to go on there, but I just woke up and think I'm missing something. I'm not sure how the stock pump is in there with Nitrous and 24's.
I'd have thought an upgrade would have been requisite for those mods.
Do you have a lean code or ever hear pinging?
If the pump is original, it would likely almost be a preventative maintenance item to replace the pump with something a little larger.
yea the nitrous kit isn't hooked up yet and i have to put a new fuel level sender in the tank so i'm going to put a 255 in there but right now i think its stock ! if my pressure is to high right now the 255 will make it higher i'm tryingto figure out why it wont adjust any lower than 43 psi ?
Apologies - After reading your post, I somehow thought your issue was that the pressure would not get up high enough (you desired 43 PSIG and it would not get that high). Once I saw the thread title again (and after some caffeine), I realized my mistake. Disregard the lean code stuff, etc I asked about.
It sounds like a stuck FPR or pinched return line, but I don't run a Kirban so I'll let the other guys answer for you. Emailing the Kirban folks might not be a bad idea.
If you have a fuel line crimping tool, you could carefully crimp the return line and see if pressure goes up even more. If it doesn't, there could be a restriction in the return line. On my '88, I had one right where the return line goes around the fuel tank edge (it was kinda pinched). I'd take a quick peek (it's a good time to make a sheath for the lines back there - if like mine, they are real close to the tank and exhaust).