BoOsTiN Dc2

i have been trying to fix my fuel pressure problem... when the vacuum is on the fpr the vacuum is approx 54psi and with the vacuum off its approx at 57-58... my question is why is the fuel pressure doesnt jump much when the vacuum is on/off... it use to jump around 15-20psi if thats correct. im using a aem fpr, aem fuel rail, stock fuel filter, greddy 720cc, bbk 255 lph fuel pump... i've tried almost everything to see what the culprit is. i changed a new fuel filter, stock fuel rail, stock fpr, stock injectors.... only thing i havent changed is the fuel pump but that is pretty brand new and i doubt thats the problem. on the dyno at WOT the fuel pressure holds at the same as idle and drops a lil and comes back up. i've posted up and couldnt really get much help beside people telling me to the the things that i've had done.... like change the fpr, change the fuel filter etc etc.... i did those already and need to know where to go from there. will hooking up the 3 bar map sensor cause that? or hooking up the resistor box wrong cause that?

MaxSterling

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tRaCeBuStAbUsTeR &raquo;</TD></TR><TR><TD CLASS="quote">vacuum is on the fpr the vacuum is approx 54psi and with the vacuum off its approx at 57-58</TD></TR></TABLE>
normal functioning fpr, but not set a stock fuel pressure. when vacuum is removed atmospheric pressure assist spring pressure in fpr raises fuel pressure. your fpr does this with the 2-3 psi increase when you unplug vacuum source.

I still dont know what youre trying to ask. AEM fpr is 1:1, so for every amoust of boost boost you should see relatively same amount of fuel pressure. what is your problem? is car leaning out? bogging? not idling? etc etc

BoOsTiN Dc2

car is reading lean with the 720cc @ 255whp... the hondata won't recognize the 3 bar map sensor... and when the vacuum is at atmosphere isn't it suppose to raise around 15psi or so? why does mines only raises about 3-4 psi when vacuum is off??

BoOsTiN Dc2

and the aem fpr is suppose to raise psi per pound of boost, which it isn't doing... its not the fpr thats defective... it can't even hold the psi... it bounces around 36-40...can't figure out what is causing it.

MaxSterling

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tRaCeBuStAbUsTeR &raquo;</TD></TR><TR><TD CLASS="quote">car is reading lean with the 720cc @ 255whp</TD></TR></TABLE>
hard to believe, check injectors or hondata program.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tRaCeBuStAbUsTeR &raquo;</TD></TR><TR><TD CLASS="quote">when the vacuum is at atmosphere isn't it suppose to raise around 15psi or so? </TD></TR></TABLE>
I answered this question already. your fpr is functioning normally. going from vacuum to atmosphere (adding air pressure) increase fuel pressure (2-3psi). which your fpr is doing.

MaxSterling

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tRaCeBuStAbUsTeR &raquo;</TD></TR><TR><TD CLASS="quote">bounces around 36-40...can't figure out what is causing it.</TD></TR></TABLE>

again this is normal. fuel pressure jumps around 1-2psi on my gauge at idle.

BoOsTiN Dc2

going from vacuum to atmosphere it only jump about 2 psi?? i remember b4 i did this setup it use to jump about 15 psi difference then right now. also the aem fpr psi wasnt going up per pound of boost like it should of