Volvo V70 D5 2003 - Railpressure Problem

If you are not a PicoScope user and want advice with a diagnostic problem then post here. Forum members may be able to help.

Volvo V70 D5 2003 - Railpressure Problem

Postby terbo » Sun Aug 14, 2016 10:21 am

Hi,

Have here a Volvo V70 Diesel that can start and drive but only to about 30% load.
When you floor it, it shuts down, sometimes it goes in default limp home Mode,
but sometimes it cuts out complete and dies and needs restart while at WOT.

MANY MANY Things were changed and done to the Car....6 Shops looked at it.

Codes stored are 2505 and 2509 that tell Fuel Pressure to low.

Blue is Regulator value at the High Pressure Pump.
Red ist CAM-Sensor
Green is Rail Pressure Sensor

At Idle the Scan tool shows about 35 000 kpa (~5000psi)
if you accel slowly, you can get it up to about 60-65 000 kpa (~9000 PSI)
According to the Infos i found it should deliver over 130 000 kpa at Max.

What could i look at to see if this is electrical oder mechanical ?

Any Ideas are welcome.
Attachments
volvo keyon-start-fullgas-keyoff.psdata
Key-Start-WOT-Keyoff
(5.67 MiB) Downloaded 12 times
Accel-3 Gear Car-complete shut-off.psdata
Complete Dies while Accel in third Gear
(5.75 MiB) Downloaded 10 times
terbo
User
User
 
Posts: 46
Joined: Sun Jul 06, 2014 2:40 pm

Re: Volvo V70 D5 2003 - Railpressure Problem

Postby STC » Sun Aug 14, 2016 10:56 am

Start your diagnosis at the Low Pressure Side of the System - Pressure and Flow

V70 2.png


I have added a Math Channel to the FRP to show its Duty Cycle.

We can see that the Fuel Pressure begins to rise then fall and then ECU is shutting down fuel to the rail

What is it that it does not like at that point ??
V70 3.png


With less filtering on the FRP

Is it possible to look at Graphed Actual & Desired PID's for FRP on this ?
STC
Zen Master
Zen Master
 
Posts: 224
Joined: Sun Sep 13, 2015 2:10 am

Re: Volvo V70 D5 2003 - Railpressure Problem

Postby terbo » Sun Aug 14, 2016 12:07 pm

YEAH....i found the result....now have to figure out why it does this....

The Intank Pump seems fine - what a wonder if replaced recently ;)

So far so good, but when you start the car, it shut off the Pump :(

The Pump is controlled by a Body Computer according to a wiring Diagramm..
Attachments
Intankpump-keyon-start-pump-offline.psdata
Pump shuts off after engine start
(1.12 MiB) Downloaded 10 times
Intankpump-keyon-wait-keyoff.psdata
KEY ON-PUMP ON-KEY OFF
(1.09 MiB) Downloaded 8 times
terbo
User
User
 
Posts: 46
Joined: Sun Jul 06, 2014 2:40 pm

Re: Volvo V70 D5 2003 - Railpressure Problem

Postby STC » Sun Aug 14, 2016 1:31 pm

Terbo

The Intank Pump seems fine - what a wonder if replaced recently ;)


"Seems Fine" is not good enough - You really need to be looking at Pressure and Flow at the back of the HP Pump.
The fact that it is "NEW" is more reason to check it properly. Chances are the previous garage took off a good one and replaced it with a cheap nasty aftermarket.

v70 5.jpg


I am sure I have seen "New" fuel pumps looking better than that on an amp clamp trace. Then the fact that it is pulling above 20 amps to get it going, Is it bad or is there a restriction it is fighting ??

v70 4.png


And there the current is dropping off to zero on cranking with (some) voltage present

Is this demand controlled with PWM on the Earth side ??
STC
Zen Master
Zen Master
 
Posts: 224
Joined: Sun Sep 13, 2015 2:10 am

Re: Volvo V70 D5 2003 - Railpressure Problem

Postby terbo » Sun Aug 14, 2016 3:41 pm

I think first of all i have to find out why the CEM is shuting of the
Fuelpump relay as soon as the car is running.
I found the relay and is closes with ignition on and
as soon as i start, it shuts of the Pump relay in the CEM in the
left front drivers footwell.

If there is no power, no pump will ever deliver any amount of fuel.
terbo
User
User
 
Posts: 46
Joined: Sun Jul 06, 2014 2:40 pm

Re: Volvo V70 D5 2003 - Railpressure Problem

Postby Dcunning35 » Sun Aug 14, 2016 4:19 pm

Does the relay drop out on crank or immediately after the engine fires? . I might be way off but what about powers and grounds to bcm . You could prove your theory by bypassing bcm relay circuit and making sure it will build max frp.
Like I say I might of misunderstood you .but I've done a couple of these with corrosion in bcm from engine connector .
Dan
Dcunning35
User
User
 
Posts: 47
Joined: Thu Jan 28, 2016 12:33 pm

Re: Volvo V70 D5 2003 - Railpressure Problem

Postby volrem » Sun Aug 14, 2016 5:44 pm

Pump runs for 90 seconds after key on and then shuts down. It's turned on if low fuel in tank (less than 25L or something like that) or on high demand (heavy acceleration). It's meant to be like that.


Measure fuel pressure before HP pump.

Can give more details on wednesday but don't focus on pump turning off.

It has delivery pump in HP pump and can run without electrical pump in tank.
volrem
Guru
Guru
 
Posts: 146
Joined: Fri Jan 03, 2014 3:43 pm
Location: Estonia

Re: Volvo V70 D5 2003 - Railpressure Problem

Postby terbo » Sun Aug 14, 2016 7:53 pm

OK, now i am really curious for Wensday.
Will test Pressure at HD Inlet this week, don´t have any
tools for that at home.
Why do they do sonething like that ? Then the Tank Pump should
kick in, when its off and i floor it ? Will look at this.
terbo
User
User
 
Posts: 46
Joined: Sun Jul 06, 2014 2:40 pm

Re: Volvo V70 D5 2003 - Railpressure Problem

Postby STC » Sun Aug 14, 2016 10:26 pm

Terbo

We have some good information from Volrem. He has excellent Volvo Product Knowledge.

No need to wait until Wednesday to test fuel Pressure and Flow "Before HP Pump" to quote him.

I would Tee in before and after Fuel filter. Perhaps force / Gravity feed the HP Pump from an external fuel supply of fresh Diesel.

Looking at your waveform, It is clear that the IMV has reached 95% Duty and the ECU has, in desperation of more fuel has sustained that for 2.5 Seconds. That engine is begging for more fuel.

I have a suspicion / theory that the 95% Duty for 2.5 Seconds is the Criteria to set the DTC, and throw the towel in ?


I know from experience that a good HP Pump with good un restricted flow from the fuel tank can achieve 1000 bar + in no time. 2.5 seconds is a long time for an engine gasping for fuel.
STC
Zen Master
Zen Master
 
Posts: 224
Joined: Sun Sep 13, 2015 2:10 am

Re: Volvo V70 D5 2003 - Railpressure Problem

Postby terbo » Mon Aug 15, 2016 6:11 am

Hi,
Thanks you...
I will get a meter and T in as you said and look what i can see.
I want to look at Injektor back leakage and the security Valve at
the end of the rail as well, if they let pressure of.
Had a leaking one on a Opel , that behaved quite similar,
but as the car was evrywhere already i would think that they
checked the "easy" things already.

Could it be a injector or the security Valve at all in your opion ?
terbo
User
User
 
Posts: 46
Joined: Sun Jul 06, 2014 2:40 pm

Next

Return to Help me fix my car

Who is online

Users browsing this forum: No registered users and 0 guests