fuel pressure help

[89ntrcptr]

ok, i just finished installing my 255 intank pump, 42lb fms injectors, pro-M 80mm mass air meter calibrated for my injectors and supercharger and powerpipe, adjustable regulator, im getting a fuel pressure gauge tomorow to check my pressure, question is what should i set it at, ill be running a f-150 crank pulley and i have a power pipe, it fires up now but has a slight sputter to it kinda like a large cam but then seems to smooth out, took it down the road nice and easy and it surges a lil bit when i come to a stop sign but nothing big, motor is stock besides the fuel system and exhaust but i just realy would like to know what to set the fuel pressure and timing at, i have no BTM and i run 92 octane, i want the most out of it but yet safe for the street. thx Justin

[5150 LX]

Right now you have way too much injector for your combo, IMHO. But the good thing is you have plenty of room to grow :D

Try working it around 40 psi and then go from there.

[89ntrcptr]

well yes it may be much for now, but this winter im going turbo, afr 185's intake and a custom cam, with 10 psi, this is just to keep me happy for the summer

[5150 LX]

All these turbo guys popping up :D

Since it's a temp. thing then I see no major issues, do you have a tuner of some sort?

[89ntrcptr]

no tuner, just have to do a base tune myself and get by for the winter, yet i dont want some slow POS, i was limited to stock boost for my stock fuel system and figured might as well go with the 42's and all now instead of buying twice, who knows maybe ill just add even more boost

[fanglemeister]

You should always run close to stock fuel pressure if you aren't tuning the eec.

The problem you are having is in the eec, "minimum injector pulsewidth" won't allow the eec to cut down pulsewidth enough at idle. Try starting out FP at 38 psi (vac off FPR), this will help the situation a little. Don't get on it right away until you've driven around some in closed loop (at least 15-20 minutes) and the eec adjusts accordingly to the lower pressure. It will start asking for greater pulsewidth to compensate, and might stop asking for idle pulsewidth under the hardwired minimum.