ok, I just swapped my 93 prelude si to a jdm h22a, and i installed an STR fuel rail and an AEM fuel pressure regulator, stock pump (for now) and stock injectors (for now), Im runnin 28psi and its still running rich!! does anybody have any idea what it SHOULD be set at... I'm kinda hesitant to go much lower but i dunno what to do... the only mods are I/H/E and AEM pulleys

 

Stock fuel pressure would be at 42 psi, but since you have a larger fuel rail and regulator, I'm not sure how much if at all that will affect fuel pressure.

 

How do you know it's rich? If you're running 28 psi fuel pressure stock pump stock injectors, then you have an injector that is stuck open or not functioning properly. Clean your plugs, go drive around, and see which injector is messed up by looking at the plugs after a short drive, also check to see if the plug is actually wet with fuel.

 

I can tell it's running rich because with the pressure set at 40psi, the motor would flood after 6500rpm, evenh at 28, it kinda bogs down at high rpm's and when I shift into 2nd, it backfires. even when I'm sitting at traffic lights or somethin, I can smell gas burning. I'll try getting some new spark plugs and looking at em after a short drive and see what that turns up.

 

I wouldn't go lower than 28, although that sounds about right for a 4th gen motor. 4th gens usually take 30-35 at idle, and 40-45 wot. the 5th gen motors run higher pressure due to smaller injectors. what ecu are you using? hows your o2 sensor look?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by IHateJDM &raquo;</TD></TR><TR><TD CLASS="quote">I wouldn't go lower than 28, although that sounds about right for a 4th gen motor. 4th gens usually take 30-35 at idle, and 40-45 wot. the 5th gen motors run higher pressure due to smaller injectors. what ecu are you using? hows your o2 sensor look? </TD></TR></TABLE>

havent looked at the o2 sensor, im using a p13 ecu, i was running the stock chip, now im using a mugen chip, but at 40psi, it flooded the motor and burnt out my distributor, went down to about 35 and it started running a little better, now down to 28 and its running even better, im just scared to keep dropping it. and remember, I'm using a high volume fuel rail so the pressure is gonna be lower than stock.

 

A high flow rail will not lower the pressure.

I wager you have a leaking injector or two. Fuel pressure on a prelude with the vacuum line off the regulator is 38 psi.

 

the fuel rail increases volume, but not pressure. I would look at your injectors first and make sure the are firing correctly. if that doesn't work, try your stock fuel rail again. OEM fuel rails can hold around 300whp before you need to upgrade, so unless you have some crazy turbo kit we don't know about, the fuel rail isn't really helping anyways.

 

stock fuel pressure is 36-40 psi on that setup. If you are running rich you have some other problem.

Get rid of the Mugen chip go back to stock. Mugen never made a p13 program anyway...

 

could i use the injectors off my old h23? i know theyre good, but will they be big enough? and how can i test my h22 injectors?

 

the h34 has 240cc injectpors, your h22 has 345cc. get rid of the computer program use a stock one or a good copy of the spoon v1 program.