4gen H22 fuel pressure
 

Just wondering what you guys are running. When I installed my B&M gauge, my fuel pressure with the stock regulator was 32psi at idle, forgot what it was at WOT. I installed the regulator and tried everything from 34-40psi idle. Right now it is in the 35 range but it feels like its running rich to me. Until you hit WOT it feels a bit sluggish. Let me know what you guys are running. 4gen H22 only.

Re: 4gen H22 fuel pressure (4bidden)
 

BUMP https://honda-tech.com/forums/images/smilies/emthup.gif https://honda-tech.com/forums/images/smilies/emthup.gif

Re: 4gen H22 fuel pressure (4bidden)
 

mine is at 30 psi at idle w/the fpr vacuum hose disconnected. that's how it should be measured at idle.

Re: 4gen H22 fuel pressure (Mikey3000)
 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Mikey3000 &raquo;</TD></TR><TR><TD CLASS="quote">mine is at 30 psi at idle w/the fpr vacuum hose disconnected. that's how it should be measured at idle.</TD></TR></TABLE>

this is wrong disconnecting the vacum hose simulates wide open throttle because the manifold looses vacum at wide open throttle. with the vacum hose dissconected the fuel pressure on a 4th gen vtec is 36-39 psi. so 35 psi with the hose connected is too much fuel.

Re: 4gen H22 fuel pressure (junbb1)
 

ya mine was like 25 at idle w/line on. i think it was about 40 wot

Re: 4gen H22 fuel pressure (junbb1)
 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by junbb1 &raquo;</TD></TR><TR><TD CLASS="quote">
this is wrong disconnecting the vacum hose simulates wide open throttle because the manifold looses vacum at wide open throttle. with the vacum hose dissconected the fuel pressure on a 4th gen vtec is 36-39 psi. so 35 psi with the hose connected is too much fuel.</TD></TR></TABLE>

so when disconnected it should read 40 psi?

Re: 4gen H22 fuel pressure (Mikey3000)
 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Mikey3000 &raquo;</TD></TR><TR><TD CLASS="quote">

so when disconnected it should read 40 psi?</TD></TR></TABLE>

if the regulator is stock it will read 36-39 psi with the hose dissconnected. so 40 psi is ok.

Re: 4gen H22 fuel pressure (fastludeh22)
 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by fastludeh22 &raquo;</TD></TR><TR><TD CLASS="quote">ya mine was like 25 at idle w/line on. i think it was about 40 wot</TD></TR></TABLE>

Are you serious!? I've never seen anyone have their fuel pressure set at 25psi at idle. I do all my adjustments with the vacuum line taken off the manifold and with my finger over it, simulating WOT. I think the WOT pressure I am running is 43ish, with it at about 32-33 idle.

I believe mine was right around mid 30's when a mechanic checked mine. It ran fine, not rich or lean.

Re: (LudeyKrus)
 

At idle or WOT? You should make adjustments for WOT since the car is consistently compensating for cruising conditions.

Re: (4bidden)
 

mine is set at 40 wot. Runs fine there

i'm not sure; i didn't do it......dang, do I need a fuel press. gauge!!!

mine's is about 32-33psi at idle and 40-41psi at WOT.

Re: (Honda Sport)
 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Honda Sport &raquo;</TD></TR><TR><TD CLASS="quote">mine's is about 32-33psi at idle and 40-41psi at WOT.</TD></TR></TABLE>

Is this with a fuel filter mounted gauge? Have you been on the dyno at all?

yes. mounted on the fuel filter. Haven't been on the dyno. when I unlplug the vaccum line to the FPR, the reading is about 40-41psi.

the 97 prelud ehelm manual says to check fuel pressure with the vacumm line dicsonnected and it should read from 47-54 psi on a gauge. i am guessing that the obd1 engines should be a little less than that since they run larger injectors.

Re: (v4lu3s)
 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by v4lu3s &raquo;</TD></TR><TR><TD CLASS="quote">the 97 prelud ehelm manual says to check fuel pressure with the vacumm line dicsonnected and it should read from 47-54 psi on a gauge. i am guessing that the obd1 engines should be a little less than that since they run larger injectors.</TD></TR></TABLE>

Yea, which is why I asked for 4gen H22 fuel pressure in particular. https://honda-tech.com/forums/images...es/emsmile.gif

Thanks for posting that info though, interesting to see just how much 65cc extra flow effects the fuel pressures.

Re: (v4lu3s)
 

I always found it funny how my car feels much better at 42 psi than in the low 30's like everyone else. However I ask this, even though my 98 has the lesser injectors it is still being run by an ODB I program which is assuming 345cc injectors. How do you think this affects performance?!? Even if I set the psi to 40+..

Re: (Jason kiDD)
 

Its also weird that I get much better gas mileage at about 36-38psi idle, 46ish WOT.

Re: (4bidden)
 

lol me too. Although the car rips when set to 42psi.. But gas goes the way of the great oil spill once I do that. I still dont even get 200 to the tank yet. But I have a CX hatch so I am smaller than most tanks..

Re: (Jason kiDD)
 

Mine is at 35 idle and 45 WOT, it pulls pretty damn hard all the way through the revs...now if i could just dig my car out of the snow!!! Its still buried https://honda-tech.com/forums/images...s/emhammer.gif

Re: (FaS4wS)
 

doesnt it say what it should be in the helms. I dont have one so i cant check.

i had hooked up a fpr once but it wasnt adjustable. It was just a dummy tach. I think mine was at 26-27 idle and like 34-35 WOT. That seems kind of low compared to everyone elses.

Im also curious to know if a 4th gen Si fuel pump puts out the same fuel pressure as a vtec model fuel pump or if they are both the same?

Re: (jdm22vtec)
 

biggity bump

Re: 4gen H22 fuel pressure (4bidden)
 

When I put my B&M FPG on my 94, it read 39psi... and that's where it's at now. I just have bolt-ons, so it works fine at oem settings.

Re: 4gen H22 fuel pressure (Que_Lude)
 

Modified by uncle at 8:39 AM 10/12/2004