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Quick question fuel!

W

Wijesunde

New member
Location
Paris
Aight man thanks for a quick reply
Fuel pressure regulator (key on /engine off)
https://imgur.com/a/hlUIQ
Normal?
When i start the engine the regulator mbar goesup slowly and the noise goes away with it
I am trying to find the cause of my cold start noise i think its definitly coming from my hpfp..

Is there any blocks i should look while key on /engine off before starting?
 
eurocars

eurocars

5/17/15 - Never forget
Location
Indianapolis
Car(s)
2006 GTI
Pressure will rise as the HPFP builds it. -31 Mbar (less than 1 PSI) is not far from zero at key off if the lp pump isnt running and has had time to bleed pressure.

Have you removed the pump and checked the cam follower for wear? There is also a chain tensioner under the HPFP housing that is a common failure on older engines
 
W

Wijesunde

New member
Location
Paris
I have checked the cam follower a month ago its was in good condition changed it to a new fallower.
the chain tensioner has been changed even the chain side casing its brand new..+ lpfp and fuel filter
Yesterday i took out hpfp again to check the cam follower its was in good condition.

I have already started a thread for this noise but still cant see where this coming from.. i got a feeling its the hpfp not operation correctly at the first start of the day.
Here u can check the my old thread http://www.golfmk5.com/forums/showthread.php?t=199706
 
707Stang

707Stang

I'm Hella From Nor*Cal
Location
Nor*Cal
eurocars said:
yes, at key on /engine off, you are basically reading low pressure values in the fuel system since the HPFP is not creating increased pressure
Click to expand...



Shouldn’t there be more pressure in the rail since it is a returnless system? I get the hpfp isn’t running but it seems there should be more residual pressure than that in the rail. If the injectors aren’t open and the hpfp is sealed the pressure has no where to go?


Sent from my iPhone using Tapatalk
 
W

Wijesunde

New member
Location
Paris
The noise fade away when the rail pressure goesup after starting.
I have one error in vagcom about fuel pump relay j17
But this relay cant be found anywhere in my car..
 
707Stang

707Stang

I'm Hella From Nor*Cal
Location
Nor*Cal
Where exactly is the noise coming from?


Sent from my iPhone using Tapatalk
 
GTI's

GTI's

Drag Racing Champion
Location
MD
Wijesunde said:
The noise fade away when the rail pressure goesup after starting.
I have one error in vagcom about fuel pump relay j17
But this relay cant be found anywhere in my car..
Click to expand...

Based on your scan this is a GTI so no fuel pump relay, you have a Lpfp control module instead.
 
W

Wijesunde

New member
Location
Paris
The noise is coming from the right side of the engine where the hpfp and cam chain..i get the noise only on first start of the day or if it has been sitting more than 8 hours..
Can some check normal fuel rail pressure with ignition on / engine off ? If you havnt started for awhile.

This is the error for j17
01259 - Fuel Pump Relay (J17)
009 - Open or Short to Ground
https://imgur.com/a/kNNrN
 
Last edited:
GTI's

GTI's

Drag Racing Champion
Location
MD
Car has not been started in weeks, engine not running.











Noise is probably cam chain / tensioner.
 
W

Wijesunde

New member
Location
Paris
Thanks for your test
The whole cam n tensioner set has been changed 1000km ago because of this noise and still happening
Thats why i am going towards hpfp.
I see you get atleast 33bar (rail pressure actual)
I get only 4.5bar..that seems very low?

When i start the car rpm get around 1200 with the noise and rpm goes down to about 1100 for about 20-30 secnds stays there then goes down to normal around 730 and noise fades away.

And also if i start the engine maf unplugged i get no noise..i have no idea how maf can pull a startup noise
I dont have alot of engine knowledge:iono:
 
Last edited:
707Stang

707Stang

I'm Hella From Nor*Cal
Location
Nor*Cal
Is the noise somewhat like a knock?


Sent from my iPhone using Tapatalk
 
W

Wijesunde

New member
Location
Paris
Idk how i can call this noise..
https://youtu.be/e_SfZdq188o

Fuel system seems fine to me?
is there any blocks i should look at when starting?

I did the pcv test by blowing through it and it seems the pcv is bad.. should this effect engine on cold startup?

I get no click when i do output test on vag for n205 valve ?
 
Last edited:
W

Wijesunde

New member
Location
Paris
What the engine does when startingup with maf unpluged other than running on map sensor?
If i unplug the maf sensor and turns the engine on i get no rattle noise like in the video
 
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