zinkrb250

So you were using a walbro fuel pump and reading 100% duty cycle?... I don't understand how a failing fuel pump would make the powerfc read 100% duty cycle... could you please explain?

anyone?? I'd be glad to answer questions to help diagnose this problem

SII rb25det -using power FC- Can't figure out why my nismo 555cc injectors are hitting 100% duty cycle when i'm only making 371horsepower... any ideas??? -Duty cycle is set at 66.5% at .14m/s lag -Fuel pressure is set at 43psi w/o vacuum -Brand new fuel filter

Yesterday I hardwired the fuel pump to the battery... It's now recieving 13. + volts and I'm still getting high knock levels in the high rpms.. I'm using a PFC and my car was tuned at a certified excel tuner facility.. So are we saying that I could be getting high knock levels because my afm is being over flowed? The reading on my pfc is saying my afm is seeing 5115mv or something along those lines... So it looks like i'm getting a new fuel pump... prolly not the nismo because it's twice as much as a bosch pump... what do you guys recommend? I see a lot of people on here using 040 and the 044...

Here is a graph from my last dyno tune... My A/F ratio is a little high and i'm getting high knock levels at high rpm... On a post earlier someone suggested that it was my walbro 255lph fuel pump that was giving out and not flowing enough fuel... However, I'm still using a sII rb25det afm and making 371hp... Would this be a problem causing my high knock levels or the fuel pump? I turned up the fuel pressure to 50psi and my injector duty cycle is set at 87.0% on 550cc injectors.

Looking for a low mileage GTR fuel pump... Would require shipping to USA Thanks Andrew

Unfortunately GTR pumps are a little hard to source here in the states... What do you think about a Supra TT pump instead?

I had the PowerFC boost controller on there but the tuner could never get it to work properly... The shop where this was tuned is an Apexi excel dealer and certified tuner... he was on the phone with Apexi telling them what was up and they couldn't even figure out why it wasn't working... he said maybe the solenoid was messed up... So right now it's just got a bleed valve on there... Which i'm not exactly thrilled about... but it gets the job done The injector duty cycle on the settings in the PFC are at 86.5%

Thanks mates! I'm extremely pleased with my results... This matches my goals perfectly... I wanted something streetable that i could enjoy at track events occasionally... As for the torque spike... i'm not sure... might have something to do with my tomei poncams? This setup I'm running is in my 95 s14... i love it! Handles beautiful on the road... the GTRS spools rather quickly for the amount of power it can push... I was wanting something to enjoy on the streets and this turbo performs just as i had imagined it... In stock form... boost would build and set you back... but then as you climbed higher into the 5-6000 rpms it seemed like it would start to drop off... Now, it just wants to go... it feels like it would just keep pulling ... i bumped up my rev limit (using my pfc) from 6900 to 7000.... But in any case i'm more than pleased with the results... My tuner informed me if i wanted to go any further with power i'd need to upgrade injectors... he said they're getting border line to the limit (i'm using nismo 550cc)

Just Got my ride tuned... here's some graphs.. Final Rear Hub Powa: 371.3 RWHB @ 13.7 PSI Final Torque: 297.8 1st Graph: Torque Curve on the Left.... Horsepower on the Right 2nd Graph: Torque Curve on the Left... A/R ratio on the Right 3rd Graph: Boost Press.

Well i took the solenoid out of the equation and it held a steady 10-11psi .... So does this mean (on the pfc h/c) that on boost setting #1 at .5kg/cm2 i should lower duty cycle from (factory) 48 to....?????? what? I have no idea how this thing works

it's definately after the butterfly

Yes.. On the H/C under settings - boost - you have about 5 different boost settings to choose from.... next to each boost setting you've got the duty cycle setting and then next to each duty cycle setting is the number 255... right now i've just got it on the lowest setting of .5 mmhg? and then 48 duty cycle.... These were the original numbers already in the pfc from apexi Wouldn't i have to be driving the car to use the multimeter to see when or if the solenoid was opening?

Correct... The wastegate vacuum is running to the "COM" port (short length of hose as recommended in the instructions) but i don't have a nipple on my intercooler piping (it's the FMIC Hybrid kit)... so instead of having the "NO" port vacuum line running before the throttle body, it's attatched to the throttle body plate that attatches to the intake plenum... here's a picture of what i'm talking about.... This is and old one before i installed the apexi solenoid but it'll still give you the right impression.... The vacuum circled in the picture is where i've got the "NO" vacuum line plumbed.... according to the apexi instructions it should be before your throttle body on the cold side of the intercooler piping

the map sensor is T'd off of the vacuum line going to my Fuel press. reg.... it reads boost fine on my hand controller... I was missing the factory boost solenoid and harness when i installed the rb25 into my s14 so i had to hardwire a 12v. source to the AFM 12v source... then i ran the earth wire from the apexi solenoid to pin 25 on the efi harness.... according the the rb25 wire schematics, pin 25 is the boost solenoid control... I can hear the apexi solenoid click whenever i turn the ignition to "on"... I get a 12v reading whenever i check for power on the apexi solenoid