My 92 Civic Si with a 93 JDM H22 swap was running normal fuel pressure (42psi) with a 190lpr Walbro intank. Put a custom turbo kit on, start it up with an inline fuel pump, same 190 Walbro, and an FMU and fuel pressure holds at 60psi now. And when you give it some throttle, instead of fuel pressure going up a little bit with throttle response, the fuel pressure drops the opposite way until boost kicks in, then it raises 12:1.

Keep in mind the FMU is one from a drag kit. center nipple goes back to the tank, side nipple to the stock regulator. Vacuum source is direct to a fitting on the back of manifold.

So i ditch the inline fuel pump and run the stock 190lpr and just turn down the boost, cause i know that stock pump wont keep up now. Same fuel pressure. Same results. fuel pressure is high and it slowly goes down a little bit with more throttle response, then it goes up with boost. It seems like if i put the car in reverse, the needle jumps down to 58psi, then back up to 60psi.

So i ditch the 190lph and get the Walbro 255lph High Pressure intake. Same thing again, but this time the fuel pressure goes up to 65psi at idle.

Is my FPR bad? Im not sure if bad FPR's increase fuel pressure. I was always under the assumption that a faulty or old one would decrease it, but mine just runs rich. Even my Defi A/f gauge freaks out and those arent even that accurate from a factory O2 reading.

suggestions?

 

bump.

someone please shed some light on this. I'm sick of running 65psi at idle. thanks

 

would like to know also.,...
found out.....
look below


Modified by 1meanB18c5civic at 5:36 PM 8/28/2004

 

yes, it will , the fuel pump will be the only source of pressure in the lines. the FPR regulates it. without it..it would increase by the pressure submitted by the pump. runnig REAL rich and finding gas in the oil is very common.