Powerfc Power/fuel Cut?

[32godzilla]

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??

[BOOSTD]

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 March 16, 2008 by BOOSTD

[paulr33]

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]

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 March 16, 2008 by 32godzilla

[paulr33]

anything is possible - once you have the hand controller all will be revealed