FREELANDER with BMW DDE Version 4.0 System

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Re: FREELANDER with BMW DDE Version 4.0 System

Postby andrewbishop66 » Tue Oct 11, 2016 7:44 pm

should be fine on the low pressure side as far as pressure goes as long as the seals /rubber pipe isn't affected by diesel

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Re: FREELANDER with BMW DDE Version 4.0 System

Postby Technician » Tue Oct 11, 2016 7:52 pm

Thanks Andrew, yes I did think about the fuel reactions and thought about petrol and how it affects the skin after contact, diesel does not seem to react the same. I'll give it a go... :)
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Re: FREELANDER with BMW DDE Version 4.0 System

Postby STC » Tue Oct 11, 2016 11:27 pm

I use a Sealey Fuel Pressure Gauge set for testing Petrol & Diesels, have done for years. does it no harm in my experience.
Granny, Suck eggs - Not wishing to, but be sure to check pressure & FLOW before and after the filter.

I don't know the strategy of that system but the ECU could deduce from Rail Pressure, Engine Speed, Engine Load & IMV Position that something is not within range. That begs the question why it wont throw a DTC for High Pressure but will for Low Pressure on the Pre Supply Side even with it pushed up, shorted to the 5v.

My guess is that they either forgot, believed it would not occur or covered it with a DTC on the HP side. That DTC guided test plan then asks for the LP side to be confirmed good. I'm either on the money or way off ??

It is the best sense I can make of it for now..

Hope that helps.
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Re: FREELANDER with BMW DDE Version 4.0 System

Postby Technician » Wed Oct 12, 2016 8:27 pm

This thread is getting a bit long now and I don't want to loose sight of the origin of the problem it came in with and the problem it has now.

If we refer back to the original post I advised that the land rover smoked, blue smoke and then cleared, and a fault code P1190 referring to the fuel rail pressure plausibility was present.

Today I checked the low side fuel pressure and can confirm that the actual pressure is roughly the same as live data, 3.47 bar using my analogue pressure gauge. Because the technical data advised the pressure should be 2.6 bar [+-] 0.2 bar and the pump being very noisy in operation, I decided to buy a Pierburg (hope that is spelled correctly) genuine fuel pump, the box had written on it Pierburg but I failed to look inside the sealed box until I arrived at work, then I opened the box, inside was a fuel pump manufactured by AI Automotive, convinced I had been duped I took it back and advised of my findings, then I was advised that the pump being made by AI Automotive is the genuine pump because they bought out Pierburg.

Checking the fuel pressure of the new pump, the pressure is now operating at 4.40 bar, the pump is quite in operation, almost impossible to hear. I changed the low pressure fuel pressure sensor for a brand new one, cleared the fault code present, the P1190 from previously, and ran the engine, immediately checking the fault codes P1260 has now returned, I cleared the code and ran the engine again and each time the P1260 immediately returns, the engine will not rev up past about 2500 rpm, but if I disconnect the low pressure fuel sensor so that the plug wiring is open circuit, P1255 code appears which refers to the low pressure sensor circuit, as can be expected, but the engine revs and runs OK.

Getting back to this low pressure fuel sensor, the Bosch part number 0261 230 046 actually cross references to a MAP sensor, information I have read advises this is not a problem, but I am somewhat confused with two areas now on this fuel system, which are;

1 / What and where controls the low system fuel pressure regulation, the pump pressure is now 4.40 bar,

2 / If a MAP sensor has a 5V reference voltage, the ground is 0V, AD advises that the terminal 3 (output) is 4.3V at idle,

then if I am getting about 2.5V at idle and the voltage drops to about 1.7V when I rev the engine, then I think I should be looking to see if the 5V reference is dropping off when I rev the engine, if not, and I have not to date found a fault in the wiring, I am leaning towards the ECM, but if that were the case I can't understand why it revs and runs OK with the low fuel pressure disconnected?

I'm sorry to advise STC that today I have not managed to do all the checks you advised, I have lost about 4 hours working time today trying to sort out my mothers sky broadband between two companies, what a nightmare, and yes that ain't even sorted, so I'm not having a good day today, but thanks for all the help and advice todate.
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Re: FREELANDER with BMW DDE Version 4.0 System

Postby EAAD » Thu Oct 13, 2016 10:48 am

Technician wrote:
AP sensor has a 5V reference voltage, the ground is 0V, AD advises that the terminal 3 (output) is 4.3V at idle,

then if I am getting about 2.5V at idle and the voltage drops to about 1.7V when I rev the engine, then I think I should be looking to see if the 5V reference is dropping off when I rev the engine, if not, and I have not to date found a fault in the wiring, I am leaning towards the ECM, but if that were the case I can't understand why it revs and runs OK with the low fuel pressure disconnected?

I'm sorry to advise STC that today I have not managed to do all the checks you advised, I have lost about 4 hours working time today trying to sort out my mothers sky broadband between two companies, what a nightmare, and yes that ain't even sorted, so I'm not having a good day today, but thanks for all the help and advice todate.


Hi technician

I recall looking at your description of the fault and my immediate response was check the 5v ref and associated values (I amended my post because, a) I thought I'd misread your post and b) I thought I didn't have enough knowledge to try to help, basically doubting my own ability.

It still doesn't sit right with me? I would try to get information other than autodata on this circuit and look again at this?
Both the 5v ref and the signal input to the ecu
Basically alter the input signal to the ecu manually and monitor the pid ..... again as been mentioned before, I don't want to teach egg sucking to my mums mum.

Kindest regards and best of luck mate.
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Re: FREELANDER with BMW DDE Version 4.0 System

Postby STC » Thu Oct 13, 2016 11:28 am

Just out of interest, what is the pressure sensor voltage with 4.4 bar in the pipes?
but I am somewhat confused with two areas now on this fuel system, which are;
1 / What and where controls the low system fuel pressure regulation, the pump pressure is now 4.40 bar,
2 / If a MAP sensor has a 5V reference voltage, the ground is 0V, AD advises that the terminal 3 (output) is 4.3V at idle,


1. See attachment
2. I would concentrate on maintaining the required 2.6 bar physically in the system, confirmed by your gauge. I suspect that the Voltage reading in AD may well be wrong. Once again, 4.3v is too close to DTC territory for my liking. Of course that could be by design, we shall see.

FL LP DELETE.JPG
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Re: FREELANDER with BMW DDE Version 4.0 System

Postby Technician » Thu Oct 13, 2016 8:11 pm

EAAD wrote:
Technician wrote:
AP sensor has a 5V reference voltage, the ground is 0V, AD advises that the terminal 3 (output) is 4.3V at idle,

then if I am getting about 2.5V at idle and the voltage drops to about 1.7V when I rev the engine, then I think I should be looking to see if the 5V reference is dropping off when I rev the engine, if not, and I have not to date found a fault in the wiring, I am leaning towards the ECM, but if that were the case I can't understand why it revs and runs OK with the low fuel pressure disconnected?

I'm sorry to advise STC that today I have not managed to do all the checks you advised, I have lost about 4 hours working time today trying to sort out my mothers sky broadband between two companies, what a nightmare, and yes that ain't even sorted, so I'm not having a good day today, but thanks for all the help and advice todate.


Hi technician

I recall looking at your description of the fault and my immediate response was check the 5v ref and associated values (I amended my post because, a) I thought I'd misread your post and b) I thought I didn't have enough knowledge to try to help, basically doubting my own ability.

It still doesn't sit right with me? I would try to get information other than autodata on this circuit and look again at this?
Both the 5v ref and the signal input to the ecu
Basically alter the input signal to the ecu manually and monitor the pid ..... again as been mentioned before, I don't want to teach egg sucking to my mums mum.

Kindest regards and best of luck mate.



Thanks for replying, I was unsure about the operation of this low fuel pressure sensor, initially I thought after looking at it that it is a potentiometer, and then decided it was, the problem came when I expected the voltage output on terminal 3 to rise under snap acceleration, but instead the voltage dropped. I had been wondering what actually controls the low side fuel system pressure, initially I thought it was the regulator in the engine pump, but then I had doubt and wondered if that regulator only controlled the high side fuel pressure, because there is no pressure regulator in the end of the Common Rail, only a FRP sensor.

I bought a new low fuel pressure sensor and at that point was advised it is indeed a MAP sensor, that caused even more confusion, because I know a MAP sensor voltage will rise under WOT operation. I have looked further into the fuel pressure sensor being a MAP sensor and apparently it is. I have decided at the moment, rightly or wrongly that the low side fuel pressure is held reasonably constant, the engine pump/rail I am to understand must be supplied with the correct volume of fuel, hence the pressure is not the primary object it seems, I could be wrong.

This part is confusing, but I believe in the confusion all mechanical problems are eliminated, think about this one for a moment. The engine ECM immediately registers P1260 when the engine is started and revved up, the code can be cleared and then will immediately return once the engine is revved up again, reads like a fuel starvation type problem one would think, but if I unplug the low pressure fuel sensor and run the engine, code P1255 is recorded but P1260 is not, and the engine runs normally and looses no power when accelerated or driven, it is normal, this suggests to me that mechanically the system is working, what do you think?

Now this part is 100% my fault, live data all along has shown me that the air mass meter grams per second are approximately 100 grams per second less than the desired grams per second, I did wonder about this and looked at back door data from the ECM, which from memory shows no fault, however I know I should have put the scope on it, but it is not in an easy accessible place. Although it is just over £100 to buy I have bought one and if it don't fix the problem then that is my fault, but on live data it is the only fault I can see apart from trying to understand now why the low side fuel pressure has increased from approximately 2.7 bar with the last pump fitted, and now 4.40 bar with a genuine pump fitted.

Thanks for your help.
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Re: FREELANDER with BMW DDE Version 4.0 System

Postby Technician » Thu Oct 13, 2016 8:17 pm

STC wrote:Just out of interest, what is the pressure sensor voltage with 4.4 bar in the pipes?
but I am somewhat confused with two areas now on this fuel system, which are;
1 / What and where controls the low system fuel pressure regulation, the pump pressure is now 4.40 bar,
2 / If a MAP sensor has a 5V reference voltage, the ground is 0V, AD advises that the terminal 3 (output) is 4.3V at idle,


1. See attachment
2. I would concentrate on maintaining the required 2.6 bar physically in the system, confirmed by your gauge. I suspect that the Voltage reading in AD may well be wrong. Once again, 4.3v is too close to DTC territory for my liking. Of course that could be by design, we shall see.

FL LP DELETE.JPG


Thanks STC, the diagram is very informative. Please read my last reply before this one, I refer to the MAP sensor and also talk about the air flow meter.
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Re: FREELANDER with BMW DDE Version 4.0 System

Postby STC » Fri Oct 14, 2016 8:00 pm

Hi Tech
Glad the diagram helped. My pleasure.
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Re: FREELANDER with BMW DDE Version 4.0 System

Postby Technician » Sat Oct 15, 2016 3:23 pm

No cure unfortunately. I tried a new air mass meter today and although the readings are now equal or above the desired g/s the fault code still appears, that is the P1260. I have run the engine without the low fuel pressure sensor connected and the engine will rev fully, a road test initially proves no problems but after a mile or so blue smoke and loss of power returns.

Had a word with AD and they think it is either a software related issue or a fault in the ECM, the ECM was what I thought some time back. The dealer wants it back tomorrow so looks like a NO FIX unfortunately. Thanks for all the help guys, very much appreciated.

Adding some test data completed today, I know I said the Land Rover is going back to the dealer, but that is sometime tomorrow and I don't like being beaten, so I thought I would try some more testing with all the new parts fitted. Here is what I have done and concluded;

Low side fuel pressure sensor;-

Static voltage tests;-

KOEO terminal [1] = 5V
KOEO terminal [2] = 0V
KOEO terminal [3] = 1.1V
KOER terminal [3] = 1.64V @ idle
KOER terminal [3] = 1.54V @ 2500 RPM (Max rev's)
KOEO terminal [3] = 2.1V (with codes cleared). [pump is running here]

Connected fuel pressure gauge into low pressure line [Return line] from Common Rail before that line connects to the Bi - Metallic Valve, with KOEO the low side fuel pressure records on the gauge [2.6] bar with the pump running.

I then completed a low side fuel volume flow test, timing the supply I found from the return line above I am receiving 1 l/m KOEO.

I have also measured the low side fuel line pressure with KOEO pump not running and found the line pressure holds 1.4 bar stable.

I have then connected the pressure gauge to the low side pressure line directly from the fuel pump and filter and completed a KOEO pressure test for the supply to the Common Rail, I recorded [2.6] bar with the pump running.

I have also completed a volume flow test of the supply line to the Common rail, I recorded 1 L/m (actual time 52 seconds).

Up to now I was quite happy everything seemed to work, but this is the problem I have now identified.

Connecting the fuel pressure gauge in series with the low side pressure line, and connecting the gauge adapter to the inlet of the supply line to the HPP, the fuel supply [low side] can now run through the gauge and record dynamic fuel pressure while the KOEO pump running, and KOER, the results;

KOEO pump running provides no fuel pressure, and
KOER provides 0.6 bar low side fuel pressure [Gauge reading]

Does it look like I have a problem with the HPP?
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