FREELANDER with BMW DDE Version 4.0 System

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Re: FREELANDER with BMW DDE Version 4.0 System

Postby Technician » Sun Oct 09, 2016 8:34 pm

STC wrote:
according to auto data injector nozzle opening pressure is 250 bar


Andrew.
I didn't see that on Autodata, I'm under the impression that this is Common Rail ?

Me neither, it is Common Rail version 4.0. The last time I had this vehicle in from the FRP sensor using electronic test equipment, the rail pressure static was 3.50 Mpa, and when engine idling was 36.70 Mpa.

Technician
Wouldn't be a bad idea to test LP fuel flow & pressure before you go anywhere near the HP side.
Once that is confirmed, Are you able to monitor Actual & Desired FRP on your scan tool ? and as above monitor LP with a gauge.

only a low pressure supply pump on the side of the fuel tank along with the filter.


On AD, there are 2 variations for that Reg No, the first one distinctly shows 2 fuel pumps - just 2 add to the confusion.
As above confirm pressure and flow on the LP side first, then move on.

I will look in Topix and report back if I find something.


STC I have been looking at the low system fuel pressure sensor fitted to this model, its the same as they fit on some of the BMW diesels, the part number of this fuel pressure sensor is Bosch 0261 260 046, I am kind of leaning towards this sensor being a MAP sensor that seems to be able to cope with pressures between 0.3 - 4.0 bar. You referred to the testing of this previously where I advised that the supply voltage was 5V, the ground terminal number 2 was 0V, and the terminal 3 was about 2.5V and dropped to about 1.7V when the engine was revved up. AD advise that the terminal 3 with the engine at idle should read 4.3V, they don't however advise if this reading should increase or reduce when engine revs are increased, but based on MAP sensor understanding the voltage level normally increases at WOT, and this sensor is reducing voltage at WOT, and fuel pressure would normally be expected to increase when the engine is revved up.
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Re: FREELANDER with BMW DDE Version 4.0 System

Postby STC » Sun Oct 09, 2016 8:53 pm

Technician & Andrew

This thread is all out of sequence now. My fault !

I edited my last post, adding about 4 paragraphs :x :x :x Whilst you guys replied.

My mistake, but please go back a few posts and re read please

Sorry and Thanks
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Re: FREELANDER with BMW DDE Version 4.0 System

Postby Technician » Sun Oct 09, 2016 9:18 pm

Thanks STC for the update, very much appreciated. I think the first two areas for me to look at based on previous work I have already done would be the low pressure fuel sensor that I fitted, secondhand, if that does not resolve the problem number 4 in your list is a favorite, my number 2 injector/cylinder originally did have a misfire and recently the engine didn't sound too sweet, and I changed the number 2 injector plug because the pins had been damaged previously by a heavy handed young lad that originally brought the Land Rover to me, he liked pulling and pushing on the injector terminal and even then I was worried he might damage the injector terminal pins, so as you can see it is a favorite for leaking fuel back into the common rail and increasing the fuel pressure, and my low pressure side has also increased to 3.47 bar.

The other areas you ask about, IMV, FRP I'll keep you posted when I check them, but thank you very much for your help and advice.

Just one question STC, Topix, is that a subscription service for technical information, I'm always on the lookout for new data.

Thanks
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Re: FREELANDER with BMW DDE Version 4.0 System

Postby STC » Mon Oct 10, 2016 12:58 pm

Andrew
I thought it was common rail as it has a fuel rail pressure sensor but under specs it has nozzle opening pressure 250 bar which i thought was strange
just checked it defiantly states common rail and nozzle opening

I think that is either a mistake or they refer to Minimum pressure required before firing injectors..??

Technician

Google "Landrover Topix"

they don't however advise if this reading should increase or reduce when engine revs are increased,

That pump is switched by a relay, not Duty or PWM so I would expect it to remain at a constant ~2.6bar at Idle or WOT. Pressure control will be a mechanical regulator within the pump assembly or upstream of it but before the HP pump, perhaps within the filter housing ???
but based on MAP sensor understanding the voltage level normally increases at WOT, and this sensor is reducing voltage at WOT

That is what is throwing me. (I have only ever seen NTC Temp sensors work backwards)
You will have to T in a gauge and look at serial data to prove or disprove its operating strategy. Perhaps use a Mityvac, that would paint a pretty picture of its design.
and fuel pressure would normally be expected to increase when the engine is revved up.

As above, if anything fuel pressures may drop slightly (on the LP Side) at times of high demand but still within the +/- 0.2 bar tolerance. The IMV and HP pump combination will take care of increased pressure requirements in the rail. As long as the IMV & HP Pump are fed correctly.

You have got LP from a Low 1.7 bar to a High 3.4 bar so I reckon you are in the right ball park. And you will need to get that right before you go anywhere near the HP side or Injectors.

Some info on your original P1260 DTC
P1260 - Low side fuel pressure sensor plausibility - Possible Causes:
1.Lack of fuel supply: blockage or pump failure etc.
2.Low pressure fuel sensor.
3.DDE4.0 ECM.
Don't you just love the detail :) :) :) Does that suggests that pressure regulation is within the pump assembly ??
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Re: FREELANDER with BMW DDE Version 4.0 System

Postby andrewbishop66 » Mon Oct 10, 2016 3:50 pm

Hi All

if you think of the map sensor as a standard 5 volt pressure sensor

in a manifold its under slight vacuum with throttle closed = low voltage

throttle open pressure rise = voltage rise

in the fuel pump situation

at say 2.5 bar = 4 volts

open throttle pressure drops in the feed system = voltage drop

If that is the situation with this one if the sensor is good and the voltage is dropping I would say the pump cant deliver enough fuel volume to maintain 2.5 bar

Please someone correct me if i have it arse about face

Thanks Andrew
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Re: FREELANDER with BMW DDE Version 4.0 System

Postby STC » Mon Oct 10, 2016 5:52 pm

Andrew
if you think of the map sensor as a standard 5 volt pressure sensor
in a manifold its under slight vacuum with throttle closed = low voltage
throttle open pressure rise = voltage rise

Indeed, that's the way pressure sensors work, certainly the majority I have come across, that would be Air, fuel, hydraulic ...... I believe you do have it correct.
Delete 3.JPG


Now I think that may be wrong information. I would expect to see 0.5v Ignition On pump NOT running as a plausibility check for the ECU then maybe something in the region of 1.1v to 3v with pump running dependant on how it is calibrated. At any engine speed if my theory on this set up holds water - this is not a demand controlled pump ??

I cannot find any info in Topix for the values we need.

4.3v at Idle is, in my opinion, too close to setting a fault code for short to Positive.

This needs to be independently verified using a gauge T'eed in, better still a MityVac as already advised. Then we can start making sense of things.
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Re: FREELANDER with BMW DDE Version 4.0 System

Postby andrewbishop66 » Mon Oct 10, 2016 7:35 pm

Hi all
How about using a 5k pot connected instead of the low pressure sensor check live data to confirm wiring integrity adjusting to max and min then set at 2.5bar fool ecu into thinking it has 2.5 bar and see if you still get fault code

my favourite is still confirm pressure with gauge though

mityvac is a good solution to confirm accuracy of the sensor I must confess its one of the tools i forget i have

Thanks Andrew
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Re: FREELANDER with BMW DDE Version 4.0 System

Postby Technician » Mon Oct 10, 2016 8:02 pm

andrewbishop66 wrote:Hi All

if you think of the map sensor as a standard 5 volt pressure sensor

in a manifold its under slight vacuum with throttle closed = low voltage

throttle open pressure rise = voltage rise

in the fuel pump situation

at say 2.5 bar = 4 volts

open throttle pressure drops in the feed system = voltage drop

If that is the situation with this one if the sensor is good and the voltage is dropping I would say the pump cant deliver enough fuel volume to maintain 2.5 bar

Please someone correct me if i have it arse about face

Thanks Andrew


Andrew, I understand the above, but my thoughts initially with the pressure sensor voltages thought it was faulty with the voltage dropping, but when I disconnected the three pin plug from the pressure sensor the engine ran OK. The fuel pump at the time of changing the sensor for the second hand one did have just over 2.6 bar as I remember it, but now the fuel pump pressure is running at 3.47 bar, so I don't think I have a low pressure problem, although the low pressure circuit is now operating too high, this is a problem, but not a low pressure problem if you see where I am coming from, and just commenting on STC's point about 4.3 volts setting a fault code, I don't think from resent experiences with this vehicle that would happen, the reason being I linked terminals 1 and 3 together thus providing the ECM with full 5V, the engine produced no fault codes and I did drive it a good distance to see if the code P1260 would return and it never did, not even now with high fuel pressure and the current P1190, referring to the common rail being high pressure. Obviously the link wire was removed.

Thanks for all your help and advice to date members, very much appreciated, I'll keep everyone informed of the outcome and any tests I complete.
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Re: FREELANDER with BMW DDE Version 4.0 System

Postby andrewbishop66 » Mon Oct 10, 2016 8:51 pm

It is a strange one be nice to know the strategy for the fault code
good luck

Andrew
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Re: FREELANDER with BMW DDE Version 4.0 System

Postby Technician » Tue Oct 11, 2016 7:16 pm

andrewbishop66 wrote:It is a strange one be nice to know the strategy for the fault code
good luck

Andrew


Working on the Td4 tomorrow, will see what happens about the strategy of the code. I never thought about this important point when testing the fuel pressure, but on the low side from the pump can I use my 014800 sykes fuel injection pressure test gauge?

It was bought brand new some 20 years ago, it is still in good working order but never thought about using it on diesel fuel type systems, any ideas anyone?
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