NS 3.2 Fuel Rail Pressue

[2freeq]

Hi,

I'm diagnosing a low power issue in my 3.2 NS after an intake manifold clean. Process of elimination has me looking at fuel rail pressure next.

Can anyone tell me what their fuel rail pressure is at idle, 2000rpm and 3000rpm?

Cheers.

[Seigried]

Did you have the same low power issue before the inlet clean?


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[2freeq]

Did you have the same low power issue before the inlet clean?


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No not at all. The car was running great when i started the clean. It's something i've done whilst reassembling it. No idea what though. I've pulled it apart 3 times investigating.

[rgrubby]

878 RPM = 4790 PSI
2047 RPM = 11059 PSI
3079 RPM = 13629 PSI


Intake manifold pressure was about 14 PSI at idle (I think) raising to somewhere in the 20s. I didn't get snapshot of those

[Seigried]

It might help if you list what you have already checked and confirmed to not be the issue.

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[rgrubby]

878 RPM = 4790 PSI
2047 RPM = 11059 PSI
3079 RPM = 13629 PSI
Intake manifold pressure was about 14 PSI at idle (I think) raising to somewhere in the 20s. I didn't get snapshot of those

The above were stationary
This screenshot was while driving. Sorry the intake pressure scale is way to high

[2freeq]

It might help if you list what you have already checked and confirmed to not be the issue.

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Ok, i have checked the
1- Map sensor and hose and into into manifold
2- Maf sensor cleaned
3- intercooler pressure test for boost leaks
4- All vacuum hose checked for splits and loose fittings
5- all electrical connections that i touch during the manifold clean
6- No fuel leaks
7- sprayed WD40 around intake manifold looking for intake leaks
8- Taken DPF off and installed DPF delete pipe as im getting a P1499 code but that came after a couple days after the low power fault when test driving
9- Waste gate actuator
10- Boost control solenoid (you can hear it slick when disconnect power and vacuum stops when disconnected.
11- Vacuum solenoid on intake side that moves the actuator for the butterflies inside bottom manifold
12- sprayed soapy water around all hose
13- replaced Suction Control Valve
14- checked all fuses

Thats everything i can think of that i've checked so far.....

[2freeq]

The above were stationary
This screenshot was while driving. Sorry the intake pressure scale is way to high
[ATTACH]43598[/ATTACH]

I am certainly not getting the same boost or fuel pressure......

need to work out is it the fuel pressure not letting it boost or the lack of boost restricting fuel pressure......

[2freeq]

The above were stationary
This screenshot was while driving. Sorry the intake pressure scale is way to high
[ATTACH]43598[/ATTACH]

My intake pressure lower than yours too

[Seigried]

Im actualy have the same fuel pressure as you stationary using torque. My engine is in bits at the moment as i have just cleaned the manifold and am cleaning the ports etc. So i cant comment on post clean. Did you check/adjust your valves?

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[Seigried]

Mine is chipped too. Not sure if it makes a diference when stationary.

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[2freeq]

Im actualy have the same fuel pressure as you stationary using torque. My engine is in bits at the moment as i have just cleaned the manifold and am cleaning the ports etc. So i cant comment on post clean. Did you check/adjust your valves?

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No i didn't touch the valves as i wasn't 100% confident so i figured i'd leave them for another day.

[Scooby]

To check you boost sensor use a a bicycle pump or similar to put some pressure into It while you watch your scan gauge or whatever you are using to see if it registers or changes.
Also atmospheric pressure is about 14psi. Some readings include absolute pressure which adds 14psi to the total.
So if you see a reading when the engine is stopped of 14psi When it should be zero it most likely is this and not a problem.

[2freeq]

To check you boost sensor use a a bicycle pump or similar to put some pressure into It while you watch your scan gauge or whatever you are using to see if it registers or changes.
Also atmospheric pressure is about 14psi. Some readings include absolute pressure which adds 14psi to the total.
So if you see a reading when the engine is stopped of 14psi When it should be zero it most likely is this and not a problem.

Ill check this, I use 2 different scan tool apps, One shows 14.6psi boost even when car is off (atmospheric pressure) the other shows zero till it registers boost or Vacuum.

Ill try them both. Thanks.

[Ky1e]

Did reply to your post on the FB page...
Have you double checked that you have the vacuum hoses for the intake runner butterflies around the right way?