Jump to content
SAU Community

Fuel Cut When Cruise

YangLIU

By YangLIU,
in Four Door Family & Wagoneers

 Share

Recommended Posts

YangLIU Rising Star

YangLIU

Posted
Posted (edited)

Hi buddies,

just changed high flow turbo and spark plugs.

now i found there is random fuel cut problem:

1. when keep around 40% throttle on acceleration and get around 8-10PSI. sometimes i will get fuel cut once suddenly, boost pressure is gone. at this time, if i press acc pedal a bit more deeply, and make more throttle, then the car will keep acceleration and make more boost.

2. when cruise on motoway at 110km/h, just keep around 20-25% throttle on acceleration. it is about 2500-3000rpm and around -5PSI. sometimes i will get fuel cut too, just suddenly feel fuel cut and boost go down to -15PSI. I need to press acc pedal more deeply then the car will accelerate. it makes hard to cruise at 110km/s. i found there is no problem when cruise at 80km/s,90km/s,100km/s.

all fuel cut problem is just a second. all i need to do is press acc pedal more deeply

i keep my eye on boost gauge and AFM voltage, no problem when i got fuel cut.

any idea for this? :woot:

Edited by YangLIU
Link to comment
https://www.sau.com.au/forums/topic/459213-fuel-cut-when-cruise/
Share on other sites
YangLIU Rising Star

YangLIU

Posted
  • Author
Posted (edited)

Just because you have it doesnt mean thats why. The P0235 code is unexpected overboost. Clear the code and see if it helps. I had a hdi ebc and didnt constantly have the code.

i heard this from somewhere:

if the car is cold, then stock ECU will not allow high boost.

so if you are running EBC, you will easily get P0235 error.

but actually when i got fuel cut, the boost is less than 12PSI. i think there is no overboost?

how about remove/block stock boost sensor (for stock boost controller, not for the gauge)?

Edited by YangLIU
YangLIU Rising Star

YangLIU

Posted
  • Author
Posted (edited)

I have removed the gauge boost sensor. I still have the boost sensor that is near the bov. Have you taken your car to a mechanic or nissan to run a consult on it.

i haven't ran on consult. I just run cell code procedure every time. any difference between consult and cell code procedure?

i think the problem is not related to stock gauge boost sensor.

Edited by YangLIU
scotty nm35 Grand Master

scotty nm35

Posted
Posted

Sounds like AFM or boost cut. Both can show up at weird times as the turbo is much larger now, more airflow for the same boost. Definitely get it on a Consult3 and let us know. If there is no real error showing up, it could just need a tune as it's hitting parts of the map it was never supposed to.

Which highflow did you go for? It might be time for an Emanage...

YangLIU Rising Star

YangLIU

Posted
  • Author
Posted (edited)

Sounds like AFM or boost cut. Both can show up at weird times as the turbo is much larger now, more airflow for the same boost. Definitely get it on a Consult3 and let us know. If there is no real error showing up, it could just need a tune as it's hitting parts of the map it was never supposed to.

Which highflow did you go for? It might be time for an Emanage...

actually i got this GCG highflowed turbo from a mate, not quite sure how they highflowed it. GCG just told me both intake and exhaust end get highflowed.

i haven't got boost/AFM cut when hit 19-20PSI. my problem always happens when boost at around -5PSI or 8-10PSI.

i cleaned P0235 error code and lower the boost level a bit on EBC.

i saw the stock boost sensor is before throttle and boost sensor (for stock gauge) is at the end of manifold (after throttle). I connected my EBC with boost sensor (for stock gauge) together at the end of manifold. im thinking shall i move stock boost sensor to the end of manifold too with EBC together, because the boost level before throttle is a bit higher than manifold (after throttle)

post-137368-0-21147000-1440556687_thumb.jpg

Edited by YangLIU
scotty nm35 Grand Master

scotty nm35

Posted
Posted

Only the MAP sensor on the BOV pipe is causing the code, and it means the sensor is seeing 21psi or more. Looks like your gauge is out by a fair bit.

The cut will be AFM, it isn't just a voltage cut, it cuts at lower voltages depending on the cell it's in on the map at the time.

YangLIU Rising Star

YangLIU

Posted
  • Author
Posted (edited)

Only the MAP sensor on the BOV pipe is causing the code, and it means the sensor is seeing 21psi or more. Looks like your gauge is out by a fair bit.

The cut will be AFM, it isn't just a voltage cut, it cuts at lower voltages depending on the cell it's in on the map at the time.

from EBC, i never hit 21psi, so i assume move MAP to manifold could resolve P0235 issue?

for AFM cut, i need to scan with consult3 later

Edited by YangLIU
YangLIU Rising Star

YangLIU

Posted
  • Author
Posted (edited)

With a Highflow you should not really be trying for boost over 19psi on the standard injectors and fuel pump. When I had my 30/71r I only ever ran 17PSI.

just saying

sweet!

any idea for the boost/afm cut when cruise on motoway or 8-10psi boost.

Edited by YangLIU

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

    • GTSBoy
      Chris' Toyota Mark ii JZX110

      By GTSBoy · Posted

      I just bent the ends of my premo plates. It even went through Regency like that after the engine conversion and the inspector (a great bloke!) just squinted his eyes and said "I didn't see that". Plates, and how they look, are just something that have zero importance to me.
    • GTSBoy
      Strange issue RB25DET wont start

      By GTSBoy · Posted

      Yeah, I would have said the same. It makes me suggest that there are other things wrong, such that the ECU is totally unhappy with the broken sensor. The only other thought here is that maybe it is shorted, which might cause a different issue to the typical "disconnected" sensor.
    • Kinkstaah
      Chris' Toyota Mark ii JZX110

      By Kinkstaah · Posted

      The fact that US/JDM plates actually fit the skyline bumpers properly is a big, big thing for me as they are the correct dimensions. Annoyingly you can't opt for a normal plate (or plate combination) in that size. You have to make up your own one, and at that point you'd still know it wasn't randomly assigned. 
    • GTSBoy
      First time Skyline owner

      By GTSBoy · Posted

      Well, really, that's any ECU, because it's not so much the ECU that the tuner connects to, but a laptop that's connected to the ECU. You have to have the tuning software installed locally. The "remote" part is essentially just remote desktop (RDP) or VNC type access. Nevertheless, if you're looking to upgrade, then you're immediately in the Haltech/Link territory, both of which can be done by any number of competent tuners here in Oz. But without a dyno, you'll definitely also need a wideband O2 sensor fitted, and you'll probably be relying on "auto" tuning a bit, where you drive it around under various loads and then apply the corrections that the ECU learns (basically applying the fuel trims that the ECU has to do to correct the mixtures). Tuning the timing is a little harder. It can be difficult to trust the old OEM knock sensors on RBs, so it is definitely best to have someone who knows what they're listening for, with knock ears (a piezo microphone connected to the engine, and and little amp and headphones so the listener can hear the angry men with hammers who live in the engine). That is more difficult to do remotely, and I suspect the only sane way is to be quite conservative on timing. But that's OK. You're probably waaaaay better off with conservative timing where you are. What is the fuel situation? 98RON available? Or low grade jungle juice?
    • hoodedreeper
      Chris' Toyota Mark ii JZX110

      By hoodedreeper · Posted

      I see your point, I didn't think too deep into it, was purely focused on the price. There's no bad blood between myself and GSM, they acknowledged the price was cheaper else where and at the time couldn't match it. 
×
×
  • Create New...