M35 Stagea Power Delivery Issue

[Ranger]

Hi All!

I hope someone can guide me in the right direction...

My M35 Stagea 2001 drives fine 95% of the time when cruising around. From slow driving right up to "very firm" acceleration (not flat out) it accelerates smoothly and without issue.

When I floor it, as it revs out, the power cuts in and out very aggressively and the car jerks because of this (it does keep accelerating while jerking). When I back off, stop and idle for 30 seconds, then drive again I get the power cutting in and out again (whether driving slowly or harder). This does not go away while I keep driving.

If I then park the car and turn it off, leave it for 20 minutes and then start back up, its back to driving fine again. It doesnt give an issue as long as I don't floor it again.

Basically its a perfect car that I cant floor it or else it spits the dummy!

Could it be fuel cut? Some form of Boost cut? AFM? Anyone else has the same issue?

Cheers,

Matt

[barnze]

Sounds like it could be the O2 senser.

[Commsman]

What mods, if any?

Stock cars shouldn't hit boost/AFM, unless a fault condition exists. Modified cars on the other hand..

[scotty nm35]

It does sound like airflow cut, but that would only happen at full throttle. Are you saying it does this at cruise also? How bad is the surging, does it feel like you just backed off the throttle completely or worse than that?

Are there any dash lights up? I am thinking it is an ABS error for some reason.

Where are you located? I think you will need some parts swapped if there is no fault code to guide you in the right direction.

[Commsman]

It does sound like airflow cut, but that would only happen at full throttle. Are you saying it does this at cruise also?.

I think he is saying that it only starts to happen at full throttle, but after it happens he can then get it to occur again at less than full throttle.

I've had this exact same thing happen to mine - hit AFM cut during launch & then under very mild acceleration it would cut out again, & again. Switch off reset would fix the low accel problem, but main fault (AFM voltage above specs) still there. I fixed mine by adjusting the voltage.

This shouldn't happen unless he has a big intake or maybe a AFM on the way out??

[Jetwreck]

Could be the crank angle sensor!

[bigkevracer]

Does hitting the AFM cut cause any long term issues?

[PN-Mad]

Hard to say Ryan - it cuts all fuel to the motor, so its like going from Full rich to no fuel instantly. Not something that is kind to the motor for a long period of time.

[bigkevracer]

Cool thanks Alex. About what I figured but once you find where it is I'm guessing it'll be alright for a few days.

[iamhe77]

Can't see it being fuel cut if you can still accelerate. Fuel cut will try to launch your head through the windscreen!

Dirty AFM? Poor earth connection to the fuel pump? Spark plugs due for a change? Maybe a small leak on your BOV/intake piping?

[bennyb110]

Could be the crank angle sensor!

My Stags had similar symtoms as described. Light throttle would be fine, WOT and the power would cut in and out. It did throw an error for crank angle sensor though.... ECU [fault code] reset would restore functionality, but with time, the interval between faults was getting shorter and shorter. The sensor was the one located adjacent to the starter motor in the transmission bellhousing. Once I swapped it out, the performance was drastically improved. Trawl around ebay in the US for parts like the sensors for our engines as they are considerably cheaper. In this instance I managed to loacted a new in box genuine crank angle sensor for $19 US + ship.

I would run the fault code procedure to identify or at least steer you in the right direction to tracking down the issue you are experiencing.

cheers

[Commsman]

I would run the fault code procedure to identify or at least steer you in the right direction to tracking down the issue you are experiencing.

Crank angle sensor now has two gongs - do this ^^ & let us know the result.

[Jetwreck]

Crank angle sensor now has two gongs - do this ^^ & let us know the result.

Another way to figure out whether its the crank angle is to unplug it completely and go for a drive to see if the problem disappears.....ps the car will be sluggish and will take about 8 turns to start.

[Ranger]

Thanks guys for weighing in. FYI the car is stock. First port of call I will clean the AFM, check all lines, solenoid, hoses, vacuum, etc and see how she goes.

It just so happens the car was spitting out the crank angle sensor error code about 10 months ago. I replaced with brand new Nissan parts for both the Cam and Crank angle sensors. I then reset the warning light and it hasn't come back on since (not even when this issue occurs and it has happened a handful of times). I try not to boot it any more.

To clarify a couple of the posts:

- Commsman is on the mark; no issues normally from low to firm acceleration and it will drive fine all day long. Once I boot it the issue occurs and then from that point forward the issue occurs throughout the rev range (whether low, medium or hard acceleration) until I turn it off and give it a rest. Turn it back on then its fine again.

- It feels worse than backing off. It feels like a pretty aggressive fuel cut or something similar like you say (probably trying to protect itself). It basically pushes me forward in my seat each time it cuts - not so much throwing me through the window but not too far off. Let's just say the Mrs shits herself before then giving me a mouthful for thrashing it and "breaking it"!

I'm based in Sydney near the city. The car could probably do with a tune too plus I've had a whining noise under hard acceleration that I haven;t been able to work out. I don't think the issues are related. I think the whining is a front wheel bearing or something similar in the front drive line

Do you guys know any specialists who are good with the stock ECU and might also be able to check the drive line whining noise? I'm hoping ill be able to work out the power cut issue myself in the meantime.

Cheers!

[scotty nm35]

Specialists? lol.

Tune the stock ecu?

I had a car here recently that would fault only on full throttle, it turned out to be the throttle pedal resistor was faulty. Symptoms sound similar.

[PN-Mad]

Whining under acceleration sounds like a turbo on the way out if afraid. Although wheels bearings are also known to go, but it would be more constant and speed dependent.