Nissan Navara fuel pressure problem

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Nissan Navara fuel pressure problem

Postby bullstar » Thu Jul 03, 2014 2:49 pm

Hi Guys,
I have a Nissan Navara 2007 model, 2.5 DCi in and it ha a problem of fuel pressure, I have taken some scope images on fuel pressure sensor and suction control valve on rear of the pump.
When the car is ok it sits around 300 bar on idle and revs good but when she starts to play up it sits at around 500 bar (and the fuel pressure dumps fuel from the rail to about 100 bar when revved).
The FPS sits at around 1v at KOEO and about 2v at idle , Could the problem be with the sensor reading 0.5v out of range thus making the fuel rail pressure to high ? Is the suction control valve failing/sticking when switching off during its cycle as in last image ?
Fault Codes were:
P1272 - Excess pressure valve of fuel system valve opened due to malfucion
P0238 - Boost pressure sensor signal to high
P0089 - High pressure fuel pump incorrect function

All codes cleared and P0089 came back.

Here are some pics ive saved.
regards Colin.

fps after warm_8.jpg
Fuel pressure sensor when in limp mode

fps check_2.jpg
Fuel pressure sensor when working ok

fps drop out_2.jpg
Fuel pressure sensor revved up

scv  2_01.jpg
Suction control valve

nava_01.jpg
Suction control valve and fuel pressure sensor
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Re: Nissan Navara fuel pressure problem

Postby Robski » Thu Jul 03, 2014 6:25 pm

Not sure what you're looking for with those captures,there's more to a SCV control than just the PCM command, like current ?
It would be advisable to capture it all in a bigger picture from good to bad.

Information available on AD online on FRP values, you do have tech info don't you ?

Carry out a pump learn clear & see what happens ?
Last edited by Robski on Fri Jul 04, 2014 7:24 am, edited 1 time in total.
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Re: Nissan Navara fuel pressure problem

Postby bullstar » Thu Jul 03, 2014 8:41 pm

Hi, I have tried a pump and ecu re learn and it didn't make any difference , I currently don't have AD at the moment so not sure what resistance should be on the fps and scv, do you think the scv has slight fault and possible sticking , not sure what the pwm should be at idle ?
I have the full capture screen but to large to upload.
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Re: Nissan Navara fuel pressure problem

Postby Robski » Fri Jul 04, 2014 7:17 am

bullstar wrote:Hi, I have tried a pump and ecu re learn and it didn't make any difference , I currently don't have AD at the moment so not sure what resistance should be on the fps and scv, do you think the scv has slight fault and possible sticking , not sure what the pwm should be at idle ?
I have the full capture screen but to large to upload.


You didn't mention that in your first post !

You need a tech info source PERIOD, otherwise how do you intend fixing problems ??

How do I know if the SCV is sticking from those screen shots alone ??
As I said previous there's a bigger picture, trim the file that's too large, but if there's no current trace in it don't bother & grab one where there is !

FRP.
KOEO - 1.0 V
Idle - 1.7 > 2.0 V
2K - 2.0 > 2.3 V

SCV.
1.5 > 3.0 ohms ( @ 10 > 60 degC(50 > 140 degF))
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Re: Nissan Navara fuel pressure problem

Postby bullstar » Sat Jul 19, 2014 9:12 pm

Hi thanks for info but now have AD :D , slight problem :oops: as fuel control solenoid ecm switched earth came into contact with the ecm earth wire going to the scv, Ive checked the ohms on scv and sits around 2.3 ohms, the switched earth is now only at earth and not switching so pump only working at full all the time. Pin data is 10 for switched earth and 29 for ecm earth, would this mistake have possibly spiked the ecu ?
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Re: Nissan Navara fuel pressure problem

Postby Robski » Sun Jul 20, 2014 2:27 pm

what's the duty cycle in live data for pressure control ?

Any DTC's ?
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Re: Nissan Navara fuel pressure problem

Postby brett nz » Fri Nov 21, 2014 1:57 am

You need to look at the duty cycle of the suction control valve and look for big jumps in amount of cycle. If valve is sticking this can cause excess pressure and make pressure valve actuate. Once they have let pressure go once they will do it more and more often. New scv and pressure dump valve.

Cheers
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Re: Nissan Navara fuel pressure problem

Postby bullstar » Sat Feb 07, 2015 12:36 pm

Hi,
Did change the scv and cured the situation, the duty cycle on mine would not change when on idle or when throttle applied so think it was jammed but thanks for your input guys :D
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