Adjustable Fuel Pressure Settings

[RyanB58]

I have the following mods: Pacesetter LTs, SLP LM2 Catback, Taylor OVC Wires, Madz28 tune with no emissions, Racetronix high flow fuel pump. I am putting on the SLP adjustable fuel pressure regulator. just wondering if anyone has advise how to set this. Never done it, so was just wondering if someone could give me some insight on the process.
Thanks

[Injuneer]

You don't need an adjustable fuel pressure regulator. When MadZ28 did your custom tune, he had to KNOW the actual fuel pressure. If you didn't tell him you had an AFPR and exactly what pressure it was set at, he would have assumed your system uses the stock FPR, and runs at 43.5psi. He set the injector flow constant in the PCM based on that assumption.

Alter the fuel pressure now, and you screw up his tune.

Why do you feel you need to adjust the fuel pressure? Even if you had a stock tune, it would not do you any good. You don't tune with an AFPR.... you tune it by adjusting the correct parameters in the PCM.

[RyanB58]

Injuneer,
Guess I misunderstood what I needed. What I now know is that I need to get it re-tuned by madz28. I should have said that the fuel pump was just installed and since it is high volume it seems to be getting too much fuel. Does this help you understand the situation? I will call monday to get a re-tune. Thanks for your help in understanding ho this works.
Thanks,
Ryan

[Injuneer]

Installing a high volume pump, unless its ridiculously large, shouldn't alter the fuel pressure. The stock FPR should be able to handle it. If you feel the FPR is the problem, simply install the new AFPR and adjust it to 43.5psi. But don't try to change it from what it was tuned for. You shoulndn't need a new tune. There's something wrong with the fuel system if it can't control the pressure properly.

[Kevin - Blown 95 TA]

Up to a point, your PCM will adjust for a rich condition, so if you are REALLY running rich, you would have to have the regulator set way too high. If you set the pressure like fred says, then you're tune should be good to go, and the PCM and O2 sensors take care of the rest. If you ever get to the point where you just need a little more injector, you could use the AFPR to up the pressure and get a retune, but the right way to go in that situ is bigger injectors. The usefullness of an adjustable AFPR is questionable for a guy who doesn't have the resources to tune his car, cause the PCM will try to correct for any change that is made to the mixture until it runs out of adjustment room. For a guy who can tune (alter the PCM) then he can adjust for a greater fuel pressure in the injector constant settings if he just needs a little more.