fuel rail pressure

[drdarthinvader]

just installed a gss341 walbro ive tested the pressure at idle and have 440kpa (63psi) with mechanical pressure gauge at idle -just wondering if i should redo the ifr's using the injector xls.spreadsheet because now its dialed in at 58psi fuel rail pressure ??

[nevinsb]

If the fuel trims are close, it shouldn't be a problem, but if you are seeing other issues with the tune, I would definitely start off there. If you adjust the IFR you are probably going to have to redo the VE tuning.

If the tune is right, I would expect to see trims in about the 8% range.

[5.7ute]

If the VE table was dialled in with the fuel pressure at 58psi, adjusting the IFR table by the spreadsheet will bring your trims back into line. If the VE table was dialled in at 63psi, but the IFR was set for 58psi, You can adjust the IFR to properly reflect your injector flow rates, and then multiply the VE table by the same amount.
Note that since timing is related to airmass you may need to readdress this table.

[mr.prick]

my experience with a mechanical FP gauge was not good.
if you are serious about wanting to know your min, max, or avg FP
then get a sensor installed in the fuel rail.
there is another spreadsheet for actual logged FP.