Jump to content
SAU Community

Recommended Posts

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

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

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

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...

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

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.

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

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


  • Similar Content

  • Latest Posts

    • Why are people so insistent on making dirty water?!
    • Fark what are the changes of that snapping like that, clean. Nek minnit, custom radiator goes in, with built in oil cooler like those discontinued PWR ones from yesterdeacades ago
    • I thought I'd do a write up on an auto transmission fluid change for a the nissan 7 speed Automatic. At some stage the genius engineers decided that the fluid in the trans was "for the life of the transmission", (which seems kind of self supporting to me) and removed the dip stick and fill tube (funnily enough there is still a casting for it). Anyway, for this job you do need 2 specialist tools in addition to regular hand tools, jack and good chassis stands. You need a way to pump fluid up to the transmission; I got one of these but there are plenty of other options: https://www.ebay.com.au/itm/364584087070 Don't trust the generic listing though, it does not come with the required adapter for the Nissan 7 Speed. You need one of these, can't do the job without it: https://navarapart.com.au/product/genuine-nissan-patrol-y62-d23-np300-navara-re7-dipstick-fill-connector1 You need a heap of compatible transmission oil. Could be Nissan, could be anything else rated for Nissan Matic S. You need at least 10 litres, I had 15 to give it a better flush... Also, you need some biiig oil catch trays, at least one of these, or bigger if possible (volume was fine, size was very marginal): https://autobarn.com.au/ab/Autobarn-Category/Tools-%26-Garage/Specialty-Tools/Oil-Service/Garage-Tough-Oil-Drain-Pan-Black-16L---GT1068/p/TO03191 Finally, a measuring jug is very useful if your pump does not have volumes marked on it, I got a 6l one: https://www.repco.com.au/oils-fluids/fluid-accessories/measuring-jugs/penrite-measuring-jug-6l-pmj006/p/A5322648 Oh, and gloves.....this stuff is horrible (not as bad as diff oil, but getting there) ....First, jack up your car.....
    • So I mentioned the apprentice, @LachyK helped take the bonnet off. We just undid the nuts on the hinges and unclipped the gas struts, then pulled the bonnet back a little as the front was catching on the front bar.  I had a good look at everything today and have removed the rams, repaired/reset the hinges and bolted it back together like it never happened. I'll do a separate write up on the repair, and I also removed the poppers from the Fuga today too to save grief down the road.....as said above it is at least $5k to repair retail. I'm also happier about my ability to prepare a race car, and less happy about Nis-nault's engineering (I can hear @GTSBoy sAfrican Americaning) because the top hose of the radiator didn't slip off.......it snapped clean off. By practice I put the hose clamp hard up against the flare on a neck to make it least likely to ever move (thanks @Neil!). I guess that puts a little more pressure on the end of the pipe as it is further away from the rad, but still, that is pretty shit. I've put it back on for now as there was a fair bit of neck still there, but obviously there is no lip on the neck any more so I don't think I'll track it again until I have a new rad. Speaking of which....more research required. It looks like Koyo makes a standard size radiator in ally which I'll grab in the meantime, but I really want something thicker so might have to go custom in the medium term (ouch) Coolant still needs a refill and I have the pressure tester on it over night, but other than a wash down of the engine bay it seems alright. And @MBS206 noted something noisy on the front of the engine and I think I agree....time for a new accessory belt and tensioners I think.
    • our good friends at nismo make a diff for it, I have one (and a spare housing to put the centre in) on the way. https://www.nismo.co.jp/products/web_catalogue/lsd/mechanical_lsd_v37.html AMS also make a helical one, but I prefer mechanical for track use in 2wd (I do run a quaife in the front, but not rear of the R32)
×
×
  • Create New...