Jump to content
SAU Community

Powerfc Power/fuel Cut?

32godzilla

By 32godzilla,
in Engines & Forced Induction

 Share

Recommended Posts

32godzilla Proficient

32godzilla

Posted
Posted

Hey ppl,

I've had my Stagea 260RS now for 3 weeks and it's started doing some strange things.

1st off, it starting backfiring/stuttering up past 4500rpm with WOT - I read through the myriads of post regarding coil packs etc and checked mine, couldn't find any cracks etc but taped them up anyway.

2nd, changed the spark plugs from the NGK V-Groove's to NGK Iridium and gapped to 0.8mm (I know they won't be any better but just wanted to change them to rule them out)

I took the car back to the car yard and was told that a hose had popped of the fuel pressure regulator which did seem to fix the problem until.... I gave it a good hard boost and now it's fuel cutting around 5000rpm. Does the PFC have a fuel cut programmed in for some reason like detonation? I put my 32 GTR stock ECU in and it runs a lot better but instead of fuel cutting it backfires/stutters as per no. 1!!! It is going into Boostworx on Thursday for a complete re-tune but was hoping to just pay for a re-tune and not a lot of diagnostics.

I've read through Pauly's tutorials on the PFC but couldn't find anything relating to my problem.

Any ideas??

Link to comment
https://www.sau.com.au/forums/topic/210578-powerfc-powerfuel-cut/
Share on other sites
BOOSTD Mentor

BOOSTD

Posted
Posted (edited)

The PFC does use fuel cut but for the rpm limiter only. Your problem sounds like "lean popping" which would explain why putting the fuel reg hose back on made it better as It would have richened the mixtures up.

I think going to the Boostworx for a tune will fix your issue. So on the right track there.

You can easily goto SETTINGS - INJ/IGN - then under IJN increase the value between 1.100 to 1.200 which will richen your mixtures by 10-20% across the whole band for a test to see if the issue goes away and hence proving a tune is required. The change will revert back to normal after the car is turned off.

You could get smarter still and goto MONITOR - 2 CHANNEL - 1 RPM, 2 AIRFLOW - then press right arrow to record the max peak. Drive upto the point that it stutters and record the AIRFLOW voltage (should be between 3 and 4.5 volts) Then goto SETTINGS - AIRFLOW - R32 Standard - find the corresponding AIRFLOW voltage and increase the mixtures 5% at a time. The points upto 5volts will all most likely need to be increased by the same amount. Don't forget to leave the highlighted bar over the correct AIRFLOW meters type before backing out of the menu. this change will save to the new values.

matt

Edited by BOOSTD
paulr33 Grand Master

paulr33

Posted
Posted

The PFC will perform fuel cut if

RPM > RPM-LIMIT in SETTING, ENG REV

BOOST > BOOST-LIMIT + 0.25kg/cm2 in SETTING, BOOST (active profile)

so if you exceed boost by 0.25kg/cm2 or go past the ENG REV it will fuel cut, otherwise it wont

when you experience the problem watch ETC, SENSOR SW CHECK and see if any sensors go black highlighted, if they do, it means the sensor is failing

32godzilla Proficient

32godzilla

Posted
  • Author
Posted (edited)

Thanks for the tips guys, unfortunately the car didn't come with a hand controller and I missed out on getting one that was on ebay last week..... guess I'll just have to wait until Thursday.

One other thing I found strange was that when I took it back to the yard they commented on the boost setting being on 15PSI, I told them I hadn't touched it and couldn't of anyway due to it being a PFC boost controller, and they advised me they reset it to 13PSI. Could they have done something dodgy?

Edited by 32godzilla

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • MBS206
      R32 GTS (RB20DE) Injectors Replacement

      By MBS206 · Posted

      If as it's stalling, the fuel pressure rises, it's saying there's less vacuum in the intake manifold. This is pretty typical of an engine that is slowing down.   While typically is agree it sounds fuel related, it really sounds fuel/air mixture related. Since the whole system has been refurbished, including injectors, pump, etc, it's likely we've altered how well the system is delivering fuel. If someone before you has messed with the IACV because it needed fiddling with as the fuel system was dieing out, we need to readjust it back. Getting things back to factory spec everywhere, is what's going to help the entire system. So if it idles at 400rpm with no IACV, that needs raising. Getting factory air flow back to normal will help us get everything back in spec, and likely help chase down any other issues. Back on IACV, if the base idle (no IACV plugged in) is too far out, it's a lot harder for the ECU to control idle. The IACV duty cycle causes non linear variations in reality. When I've tuned the idle valves in the past, you need to keep it in a relatively narrow window on aftermarket ecus to stop them doing wild dances. It also means if your base idle is too low, the valve needs to open too much, and then the smallest % change ends up being a huge variation.
    • Haggerty
      RB25DE NEO with Haltech ECU

      By Haggerty · Posted

      I guess one thing that might be wrong is the manifold pressure.  It is a constant -5.9 and never moves even under 100% throttle and load.  I would expect it to atleast go to 0 correct?  It's doing this with the OEM MAP as well as the ECU vacuum sensor. When trying to tune the base map under load the crosshairs only climb vertically with RPM, but always in the -5.9 column.
    • CF.Panda
      R34 25GT Engine Light 21

      By CF.Panda · Posted

      AHHHH gotchaa, I'll do that once I am home again. I tried doing the harness with the multimeter but it seems the car needed a jump, there was no power when it was in the "ON" position. Not sure if I should use car battery jump starter or if its because the stuff that has been disconnect the car just does send power.
    • Haggerty
      RB25DE NEO with Haltech ECU

      By Haggerty · Posted

      As far as I can tell I have everything properly set in the Haltech software for engine size, injector data, all sensors seem to be reporting proper numbers.  If I change any injector details it doesnt run right.    Changing the base map is having the biggest change in response, im not sure how people are saying it doesnt really matter.  I'm guessing under normal conditions the ECU is able to self adjust and keep everything smooth.   Right now my best performance is happening by lowering the base map just enough to where the ECU us doing short term cut of about 45% to reach the target Lambda of 14.7.  That way when I start putting load on it still has high enough fuel map to not be so lean.  After 2500 rpm I raised the base map to what would be really rich at no load, but still helps with the lean spots on load.  I figure I don't have much reason to be above 2500rpm with no load.  When watching other videos it seems their target is reached much faster than mine.  Mine takes forever to adjust and reach the target. My next few days will be spent making sure timing is good, it was running fine before doing the ECU and DBW swap, but want to verify.  I'll also probably swap in the new injectors I bought as well as a walbro 255 pump.  
    • AnimalGarage
      spot the stagea

      By AnimalGarage · Posted

      It would be different if the sealant hadn't started to peel up with gaps in the glue about ~6cm and bigger in some areas. I would much prefer not having to do the work take them off the car . However, the filler the owner put in the roof rack mount cavities has shrunk and begun to crack on the rail delete panels. I cant trust that to hold off moisture ingress especially where I live. Not only that but I have faded paint on as well as on either side of these panels, so they would need to come off to give the roofline a proper respray. My goal is to get in there and put a healthy amount of epoxy instead of panel filler/bog and potentially skin with carbon fiber. I have 2 spare rolls from an old motorcycle fairing project from a few years back and I think it'd be a nice touch on a black stag.  I've seen some threads where people replace their roof rack delete with a welded in sheet metal part. But has anyone re-worked the roof rails themselves? It seems like there is a lot of volume there to add in some threads and maybe a keyway for a quick(er) release roof rack system. Not afraid to mill something out if I have to. It would be cool to have a cross bar only setup. That way I can keep the sleek roofline that would accept a couple bolts to gain back that extra utility  3D print some snazzy covers to hide the threaded section to be thorough and keep things covered when not using the rack. 
×
×
  • Create New...