so i went to go tune my car today and got a base run and couldnt really do much cause i had a few problem. one is that the fuel pressure drops a little during boost and vacuum problem. its also saying its running lean on 720cc even when we maxed out the injectors. and also the 3 bar map sensor is having problem. i think either its not reading boost correctly or it won't recognize it. i'm gonna try to change the fuel filter to try to see does it fix the fuel pressure, and check to make sure is there any vacuum leak. my setup is listed below

ls b16 vtec
81.5mm 9:1 endyn rw piston
eagle rods
itr intake manifold
jg throttle body
act 4 puck
12lb flywheel
turbonetics t3/t4 .57 trim ar63
drag3 manifold
hks 40mm wastegate
greddy type r bov
spearco FMIC
bbk 255 lph fuel pump
aem fuel rail
aem fpr
hondata stage 2
3 bar map sensor

base run was at 255whp @ 9-10lbs

didnt really get to tune it, i have to fix all the problems then go back and tune it.

 

what kind of vacum problem are you having? and how much fuel pressure do you loose under boost?

 

at idle its at about 40 psi then it jumps from 40 to around 36 and keep bouncing around... i have the aem fpr and the tuner said it should go up during each pound of boost. and when its at idle and i pull the vacuum off the psi moves about 5 or less

 

I wonder if the diaphram has ripped perhaps?

I know those have a problem with that.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tRaCeBuStAbUsTeR &raquo;</TD></TR><TR><TD CLASS="quote">at idle its at about 40 psi then it jumps from 40 to around 36 and keep bouncing around... i have the aem fpr and the tuner said it should go up during each pound of boost. and when its at idle and i pull the vacuum off the psi moves about 5 or less</TD></TR></TABLE>

Try out a stock regulator and see what happens. your tuners right, fuel pressure should go up 1psi for every lb of boost. most likely something wrong w/ the regulator and its not raising the pressure. Does it ever get flooded? usually when the diaphram's break your car will get fuel in the vacum lines and it will drive shitty.

 

if you have real mangament why bother with an aftermarket 1:1 fpr. Stock ones seem good to me.

 

i tried out a stock fpr and same thing, change the fuel filter still same thing, check the fuel pump (bbk hi volume 255 lph) still same thing. when i pull the vacuum off the fpr it drops about 7-8 then it comes back up to like 4-5 psi... so say im at 60 psi it drops to about 53-54 then goes back to 56 or so

 

anybody else know why i have this problem?? come on you hondata tuners out there!!!

 

You're running lean with those 720's at 255whp? Hmmm, interesting. Are you getting any funking readings from your hondata system? Make sure you have the correct 3 bar map sensor.

 

yeah i have the right 3 bar map sensor... what do you mean by funking reading?

 

how is your fuel pump wired up? has your car had any electrical problems ever?

 

yeah it had a little electrical problem but i believe its fixed already. there is no sign of electrical problem as of now

 

Check and see how much voltage is getting to your pump..

 

we checked it at the dyno... at first it was fluctuating between 12v to around 8 or so i think... and now its getting constant 12v

 

damn dude i guess im stumped then.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tRaCeBuStAbUsTeR &raquo;</TD></TR><TR><TD CLASS="quote">i tried out a stock fpr and same thing, change the fuel filter still same thing, check the fuel pump (bbk hi volume 255 lph) still same thing. </TD></TR></TABLE>

Put a different pump in there. I've seen brand new walbro pumps go bad many times.