hey guys, having a bit of trouble with my fuel pressure, i was getting it tuned on hondata s100 and everything was fine untill we got up toward the 340 whp range then we found that my fuel pressure was starting to slowly die off around the 6000 rpm range, the a/f ratio was reading between 10 and 11.5ish then once it got up to around 6000 rpms it started to lean out and went up to high 12's
iv sent my rc 750's to rc to get serviced so they are fine and i know the injectors can handle close to 500whp, also the pressure at the filter is fine at idel its 51 psi and goes up to mid 60's at full boost, i also checked the return line and that is fine, the only thing i can think of is the regulator (any way i can test it?) the car runs great other than that. please help thanks

 

ever replace the fuel filter? It can be clogged and not allowing enough fuel to flow through it, its possible to build pressure and still not have enough flow. Give that a try

 

sorry i forgot to say, i did replace my filter

 

recently? I know it sounds dumb but it only takes one bad tank of gas and one time running it to the bottom of the tank. Also what kind of Fuel Rail do you have?

 

brand new filter and stock rail
i was told something about a fuel dampener in the line from the filter to the rail and i should take it out, i didnt even know i had one in there ever hear of this?

 

aright its getting late but when your looking at it tomarrow try to think in more of a way of what can be restricting the flow, with problems like this during higher rpms thats usually what is causing it, not lack of pressure.

P.S. You do have an aftermarket fuel pump right?

 

The stock rail maybe be causing the problem, im not positive on how well they handle a heavy fuel load. Yeah many people keep it on, there is no reason to take it off. It has 1 main job, which is usefule, to dampen the pulsations of pressure inside the lines.

 

yup i have a walbro 255

 

ttt

 

bump

 

adjustable fuel pressure regulator?

 

stock, that was one thing i was woundering if i needed but i want to know if it could be anything else before i go blow 200 bucks on an afpr

 

any hondata tunners

 

proper fuel pressure is read off the fuel rail not the filter and your regulator does sound like the reason if you disconnect the vaccum on the regulator it will raise your fuel pressure buy like 10psi

 

i also knowticed that in 4th and 5th gear at the same rpm and full boost it is in the 10s to low 11s why does it only do it in 3rd gear sounds like tunning but im not sure

 

why did you go with th s100 you should have at least the s200 if you are putting down that kinda HP. it just has more fine tuning capability. in mop if u r planning to see 500 hp and are doing all the tuning on a fwd dyno you should have the s300j will full tuning options. it will really make a difference in the long run. and make sure they are not giving you a base map and are tuning your ecu to your motor setup and yours alone.

 

ill keep that in mind when i go back on the dyno on saterday ill post my results thanks alot H-T