fuel delivery system

[rahul singh]

Porsche uses return less fuel delivery system.. Any idea how to check fuel delivery rate...?

As my seniors told me that it should be around 800 ml within 14 seconds....

[lewisweller]

3 minutes ago, rahul singh said:

Porsche uses return less fuel delivery system.. Any idea how to check fuel delivery rate...?

As my seniors told me that it should be around 800 ml within 14 seconds....

 

[rahul singh]

Thanks for this video, explains a lot....

according to this guy, 800ml within 15 seconds, from individual pump........

Is this value is gonna be same for cayenne S , turbo & GTS also ?

 

[lewisweller]

35 minutes ago, rahul singh said:

Thanks for this video, explains a lot....

according to this guy, 800ml within 15 seconds, from individual pump........

Is this value is gonna be same for cayenne S , turbo & GTS also ?

 

All the same yes. 

[rahul singh]

11 minutes ago, lewisweller said:

All the same yes. 

ok.... It means for all cayenne, cayenne s & turbo... the low pressure circuit is same, The only difference appears in high pressure circuit side.. as Cayenne S is equipped with a 3 piston pump having max  delivery rate of 180 Ltr/hour & Turbo has a 6 piston pump which has a delivery  rate of max 245ltr/hour.

 

[lewisweller]

1 hour ago, rahul singh said:

ok.... It means for all cayenne, cayenne s & turbo... the low pressure circuit is same, The only difference appears in high pressure circuit side.. as Cayenne S is equipped with a 3 piston pump having max  delivery rate of 180 Ltr/hour & Turbo has a 6 piston pump which has a delivery  rate of max 245ltr/hour.

 

Up to 2006 all models used only in tank primary and secondary pumps. 

Later models have the hpfp located at the back of bank 2. 

Yours is 2005 turbo I believe so you won't have hpfp.

Your set up will therefore be exactly the same as the you tube video posted above.  

[rahul singh]

On 7/3/2017 at 9:30 PM, lewisweller said:

Up to 2006 all models used only in tank primary and secondary pumps. 

Later models have the hpfp located at the back of bank 2. 

Yours is 2005 turbo I believe so you won't have hpfp.

Your set up will therefore be exactly the same as the you tube video posted above.  

This time it was porsche cayenne turbo 2005( mileage 44k kms). Initially during starting at idling RPM is varying by itself(gauge goes up and down), now when we left it at idling, this problem reduces after 30 minutes and once engine heats up, this problem dissappers.

Now when we try to restart it sometime it starts normally, but sometime does not starts, although cranks around 3 seconds. battery volts is ok, no faults in PIWIS tester. Checked the fuel delivery rate, it is good, while checking the pressure(we did pressure check at the right passenger seat side by disconnecting the pipe goes to engine side ahead), during the idling it was showing around 4 bar, which i assume is gud as per manual.. but when we were checking for the pressure holding capacity of pressure regulator, it was not gud( as pressure was dropping quickly from 4 bar ), so changed the regulator, checked again but no success this time, pressure was dropping in the same way as earlier, now we did some visual checkups  for cracked tubes inside fuel tank, nothing abnormal spotted. 

Checked misfire, nothing detected on PIWIS tester..

 

Any idea what to do next???/?   

[TomBelgium]

It drops to 0 bar?

[lewisweller]

12 hours ago, rahul singh said:

This time it was porsche cayenne turbo 2005( mileage 44k kms). Initially during starting at idling RPM is varying by itself(gauge goes up and down), now when we left it at idling, this problem reduces after 30 minutes and once engine heats up, this problem dissappers.

Now when we try to restart it sometime it starts normally, but sometime does not starts, although cranks around 3 seconds. battery volts is ok, no faults in PIWIS tester. Checked the fuel delivery rate, it is good, while checking the pressure(we did pressure check at the right passenger seat side by disconnecting the pipe goes to engine side ahead), during the idling it was showing around 4 bar, which i assume is gud as per manual.. but when we were checking for the pressure holding capacity of pressure regulator, it was not gud( as pressure was dropping quickly from 4 bar ), so changed the regulator, checked again but no success this time, pressure was dropping in the same way as earlier, now we did some visual checkups  for cracked tubes inside fuel tank, nothing abnormal spotted. 

Checked misfire, nothing detected on PIWIS tester..

 

Any idea what to do next???/?   

The regulator is supposed to hold 3 bar after 10 minutes. After that the manual I don't think specifies a drop but needless to say it won't hold for ever. I don't think the regulator was the problem as you confirmed after changing it didnt improve. Sounds more likely related to temperature sensor or vacuum leak which more likely.  Smoke test your intake using the map senosr hole and bag off the pipes from the air boxes to seal up the system to retain the smoke. Search here I posted picture when I did mine. 

[rahul singh]

12 hours ago, lewisweller said:

The regulator is supposed to hold 3 bar after 10 minutes. After that the manual I don't think specifies a drop but needless to say it won't hold for ever. I don't think the regulator was the problem as you confirmed after changing it didnt improve. Sounds more likely related to temperature sensor or vacuum leak which more likely.  Smoke test your intake using the map senosr hole and bag off the pipes from the air boxes to seal up the system to retain the smoke. Search here I posted picture when I did mine. 

ok. I will check this method, will update you.