DreameD Posted September 10, 2018 Share Posted September 10, 2018 Hi guys! Hippo needs rescue. Please help! Freelander 2004, TD4, manual. 93k. I keep getting the same code P1190- Fuel Rail Pressure Plausibility. Car starts limping usually in second and third gear around 2k revs +/- I tried many things already, cleared the code, but so far it keeps coming back when I go for a ride..... UNLESS I disconnect the fuel rail pressure sensor. Without the sensor connected the car doesn't limp anymore. Code comes with MAF disconnected for example. Injectors are fine. I do get live readings of 350+Kpa for LP and 26k+ at idle for HP pump, which goes up to 120k. Can't go past 3k revs in 5th gear, 70MPH. Unless downhill. I have videos if you need more evidence. But maybe you guys can explain why car doesn't go in MIL limp mode when fuel pressure sensor is disconnected. I checked the cables. They have 5v and 0.5v return at ignition. Can this mean 100% the sensor is broken? Any help sooo much appreciated!! I've been dealing with this for some time and have no idea what can be wrong. And how can I test what is broken.... Quote Link to comment Share on other sites More sharing options...
Ally V8 Posted September 10, 2018 Share Posted September 10, 2018 In my experience its usually a cabling or connector fault. Rarely the sensor itself.There is even a replacement overlay harness as a fix from LR. Quote Link to comment Share on other sites More sharing options...
DreameD Posted September 11, 2018 Author Share Posted September 11, 2018 (edited) 11 hours ago, Ally V8 said: In my experience its usually a cabling or connector fault. Rarely the sensor itself.There is even a replacement overlay harness as a fix from LR. I wish that was true. The harness was replaced already. The sensor gives readings and the fault P1190 is not about the sensor...it's about the pressure. When I disconnect the sensor I get P1191, which is the sensor itself. But...as I said, I wish it was just the cable. And tests should confirm the cables fault.. However, cables check OK for continuity and voltage. One interesting thing though: The only thing I can do to avoid getting limps and MIL... is to disconnect the high pressure sensor. The car works fine without it. I mean as good as it gets without the sensor. I don't just want to replace it based on an assumption. The sensor gives readings after all.... Also I suspect pressure regulator as a possible culprit. If pressure regulator controls the high pressure sensor in any way, or vice versa then, any of the two can be broken . Yesterday for example, I saw something unusual. Just before engine cut off in traffic as I was accelerating, pressure regulator current went to 4V. Then car died. Very unusual high current. The load was not that big.... Most times under high load regulator goes up to 2.5V... Maybe it was an effort to increase pressure.... So that makes high pressure pump faulty.... But then... why is car not limping when common rail sensor is disconnected... Edited September 11, 2018 by DreameD grammar Quote Link to comment Share on other sites More sharing options...
Ally V8 Posted September 13, 2018 Share Posted September 13, 2018 I think you are confusing yourself slightly. First off, the engine ecu uses the rail pressure sensor to dictate what to output to the fuel pressure regulator as closed loop control. So when you disconnect it the ecu just uses a default value based on other sensor values such as rpm,coolant temp,airflow and driver demand etc. You are measuring voltages I assume with a multimeter,so are seeing average voltages based on the fairly slow refresh rate of the meter. There are only really two ways to sort this out,firstly the parts shotgun, if I had no choice but to do this I would replace the pressure regulator first,its way more likely to fail than the sensor. The better way to sort it is to use an oscilliscope,with this you would be able to see the duty cycle of the square wave of voltage applied to the regulator, plus the varying output from the rail sensor.With a decent scope you can then freeze frame the waveforms and see what pressure a duty cycle of say 70% on time produces as a pressure reading at a given rpm. The rail sensor should show a voltage output of 0.5v key on,engine off. This should rise rapidly upon cranking,once above about 1.2-1.4v there is enough pressure for the ecu to start firing the injectors.The voltage should then rise to about 4.5v with a wise open throttle and immediately come back down on releasing the pedal. That is the theory,however when I had a problem with a non starting TD6 RR a few years back I found that the ecu would fire each injector 3 times whatever the rail pressure as soon as it was cranking.(Analog to digital converter unit was at fault inside the ecu in that case) But the principle is the same,0.5v raising to about 4.5v max. The reason you don't get a check engine lamp with the sensor disconnected is because the software in the ecu does not command it for that fault,I don't think LR ever listed,(As they do for later cars) a fault code list that shows command Mil yes/no, plus a detailed description of possible fault causes. Quote Link to comment Share on other sites More sharing options...
DreameD Posted September 17, 2018 Author Share Posted September 17, 2018 (edited) On 9/13/2018 at 1:04 PM, Ally V8 said: The better way to sort it is to use an oscilliscope,with this you would be able to see the duty cycle of the square wave of voltage applied to the regulator, plus the varying output from the rail sensor.With a decent scope you can then freeze frame the waveforms and see what pressure a duty cycle of say 70% on time produces as a pressure reading at a given rpm. Thanks for your answer. Unfortunately I don't have an oscilloscope. I've already tested the pressure sensor in terms of voltage and I get those voltages you mentioned. But testing the pressure regulator is harder, especially because it's hard to reach. Is there any other way to test the pressure regulator, without an oscilloscope? I have a multimeter and a diagnostic tool Icarsoft LRII , thats it. No graphs unfortunately. At most I can connect the multimeter to the regulator, but then...The issue occurs only under load (rarely if I just rev the engine stationary). So how can I test the regulator while driving?:D The only two things left before blaming the HP pump are the pressure regulator and the throttle sensor. The engine knock/limp and rattle happens not only when I accelerate but also when I release the pedal (sometimes abruptly) and never happens on idle. Also the pedal live readings are very random and don't always show a value based on input. Same goes for the regulator. Sometimes it goes to 4. Sometimes just to 2, under relatively same load. At idle is 0.71. (Is it ampers or volts for pressure regulator current btw?) Of course I cant exclude the pressure sensor itself. But basically with pressure sensor disconnected: I understand why the P code/MIL doesnt come up....because the sensor generates it. What I don't understand is why the engine doesn't rattle or knock under load when it's unplugged. So far it seems the sensor generates that knock. It's either by sending mixed signals to regulator...orrr the regulator can't cope. Any other option? I still believe this is a very valuable clue. The fact that car doesn't choke if it doesn't know the value of the pressure means something is working at least. Can I know 100% something is not broken (HP Pump) just because car works without high pressure sensor? Also I see the high fuel pressure values oscillate alot. Even at idle....the pressure is never stable...they go up and down. 25-28k Kpa. And under load, it's all over the place. But maybe that's not relevant. I will try to disconnect the regulator itself and check the O rings as I've heard they go bad sometimes. Can I determine if it's faulty just by looking at it? I suspect the O rings will look normal. Obviously if they are broken I will see, however I doubt car would start if that's the case. If they look normal, I'll just put it back :)) Edited September 17, 2018 by DreameD Quote Link to comment Share on other sites More sharing options...
Ally V8 Posted September 19, 2018 Share Posted September 19, 2018 Without a scope you are just guessing. As I see it you either need to find a decent garage that really does understand Bosch common rail ,(Fail as we call it) maybe even a dedicated Bosch fuel shop ? Or you can just replace the regulator on the pump. From the symptoms you describe that is the most likely component. Unfortunately a multimeter is of very limited help with what you are diagnosing. Please use either OEM or genuine parts for these repairs,there are some horribly cheap and nasty parts on offer,these will either fail quickly or muddy the waters even more. Quote Link to comment Share on other sites More sharing options...
DreameD Posted September 19, 2018 Author Share Posted September 19, 2018 6 hours ago, Ally V8 said: Without a scope you are just guessing. As I see it you either need to find a decent garage that really does understand Bosch common rail ,(Fail as we call it) maybe even a dedicated Bosch fuel shop ? Or you can just replace the regulator on the pump. From the symptoms you describe that is the most likely component. Unfortunately a multimeter is of very limited help with what you are diagnosing. Please use either OEM or genuine parts for these repairs,there are some horribly cheap and nasty parts on offer,these will either fail quickly or muddy the waters even more. can you recommend any inexpensive scope I can get? Maybe on Amazon/ebay? Quote Link to comment Share on other sites More sharing options...
Ally V8 Posted September 19, 2018 Share Posted September 19, 2018 Sorry, my scopes are Pico 2 and 4 channel - bit much to do a single job. As much as I hate the parts shotgun, I think you might be better of in this case. I see Island 4x4 do a Bosch pressure reg for your car at £85+Vat. Quote Link to comment Share on other sites More sharing options...
smallfry Posted September 19, 2018 Share Posted September 19, 2018 24 minutes ago, Ally V8 said: Sorry, my scopes are Pico 2 and 4 channel - bit much to do a single job. As much as I hate the parts shotgun, I think you might be better of in this case. I see Island 4x4 do a Bosch pressure reg for your car at £85+Vat. Look again at the Island 4x4 listing. They call it the pressure regulator, but the photo shows what looks like the rail sensor to me ? Would need to confirm what you would be getting ! Quote Link to comment Share on other sites More sharing options...
Ally V8 Posted September 20, 2018 Share Posted September 20, 2018 10 hours ago, smallfry said: Look again at the Island 4x4 listing. They call it the pressure regulator, but the photo shows what looks like the rail sensor to me ? Would need to confirm what you would be getting ! You are quite right,I didn't look at the photo,only read the part listing - Which is clearly wrong. Quote Link to comment Share on other sites More sharing options...
DreameD Posted September 28, 2018 Author Share Posted September 28, 2018 On 9/19/2018 at 11:08 PM, Ally V8 said: Sorry, my scopes are Pico 2 and 4 channel - bit much to do a single job. As much as I hate the parts shotgun, I think you might be better of in this case. I see Island 4x4 do a Bosch pressure reg for your car at £85+Vat. Update: I decided to go for the O rings first. I have to 2 questions. I couldn't find a thread that explains how to repair the pressure regulator valve for TD4, using the repair kit. I managed to take the regulator out with hard work. I have the repair kit 2-O rings. green and white I cant seem to be able to take the white O ring out of the regulator. It's very plastiky...not rubbery... Question is how do I take it out and how do I put the new one in. The regulator filter at the tip of the regulator seem to be way bigger than the O ring diameter. 2 questions: 1. Any guides around on how to do it? 2. Any way to test the regulator functionality using a battery and a meter? I checked the regulator resistance and it's around 2.8 ohms. I connected the regulator to 3.7V/ 7.2V and 10.4V batteries in this order. I could hear a click inside the regulator but can't see anything happening :)) I wanted to see if the diaphragm of the regulator is ok and not leaking, but it seems I can't really see that. Quote Link to comment Share on other sites More sharing options...
Ally V8 Posted October 5, 2018 Share Posted October 5, 2018 Sorry can't help you with the o rings, I've only ever replaced the whole thing - that was several years ago... Quote Link to comment Share on other sites More sharing options...
Worcester Posted July 25, 2019 Share Posted July 25, 2019 Hi DreameD, did you finally resolve the issue - what was it? and how did you fix it? Thx Quote Link to comment Share on other sites More sharing options...
Worcester Posted August 2, 2019 Share Posted August 2, 2019 Hoping that this will wake up the thread My problem is the same, 06 Td4 Auto L314 (aka FL1) I am aware of at least 3 others with a similar problem What are ALL the possible causes of a fault code, read using a Hawkeye Total, and the actual fault and solution?: DTC No: P1190 Fuel Pressure Plausibility. Governer Deviation versus Engine Speed to High Only comes on after engine is thoroughly warmed up (4-5 miles) and go over 2500 revs, resetting it and it quickly comes back, Leave it long enough and the MIL comes on. Let it cool down, and it repeats as above, i.e. problem only when warm. driven 5 miles or so. It will hold the higher revs when cool. Changed the Fuel Pressure sensor, same Changed the fuel filter, same, (rear offside wheel well) Checked low pressure pump, A) plenty of flow, b) maintains a consistent 320-350Kpa (3.2-3.5 bar) Changed the Fuel Pressure Regulator Cleaned the not dirty or clogged Fuel Pickup (Sender) in tank filter. New Air Filter, New Oil Filter, modified crankcase breather Still has the problem - what is left ? I found this on a BMW forum, don't know if it is / maybe the solution? BMW.pdf Quote Link to comment Share on other sites More sharing options...
d-9 Posted August 29, 2019 Share Posted August 29, 2019 Did you get any further with this Worcester? I've got a freelander with the same issue. Changed the sensor today, no difference. Tested the sensor from the ecu connector with scope, all seems fine and in spec. Low pressure side is showing 3.5-3.7bar. When it goes into limp mode, I'm seeing a big gap between requested and actual pressure, requested typically 1200bar actual typically 800bar. At this point I think it's either the high pressure pump or the regulator. Quote Link to comment Share on other sites More sharing options...
Worcester Posted August 31, 2019 Share Posted August 31, 2019 On 8/29/2019 at 10:53 PM, d-9 said: Did you get any further with this Worcester? I've got a freelander with the same issue. Changed the sensor today, no difference. Tested the sensor from the ecu connector with scope, all seems fine and in spec. Low pressure side is showing 3.5-3.7bar. When it goes into limp mode, I'm seeing a big gap between requested and actual pressure, requested typically 1200bar actual typically 800bar. At this point I think it's either the high pressure pump or the regulator. So, swapped the High Pressure fuel pump with a Bosch Refurbished one from TTAutos, Now the fault only occurs after about 1 1/2 hours of driving!! Once triggered though is easy to trigger again. So difficult now to replicate Needed one of these: https://www.amazon.co.uk/Diesel-Injection-Removal-Sprocket-Breaker/dp/B00O0W0KEU/ref=sr_1_3?crid=F1443FJ9S01N&keywords=bmw+fuel+pump+tool&qid=1567246326&s=gateway&sprefix=bmw+fuel+pump+tool%2Caps%2C441&sr=8-3 Interesting / disappointing to find out that a lot of BMW drivers experience the same problems, so assumed was a generic common rail problem, Found this site though: https://www.pfjones.co.uk/troubleshoot-a-diesel-engine.html Quote Link to comment Share on other sites More sharing options...
d-9 Posted September 11, 2019 Share Posted September 11, 2019 I swapped out the high pressure pump, pretty easy job with the special tool, took about 3.5 hours. Since then the car has done about 100 miles, with no sign of the fuel issue it was having. It hasn’t done 90minutes straight, so cant say if it will have the same issue that yours has, but so far its looking positive. Quote Link to comment Share on other sites More sharing options...
Cata_L89 Posted November 20, 2019 Share Posted November 20, 2019 Hello, same problem here on a LR Freelander TD4, 2003, after 2000 rpm mil comes on and reduces engine power, after 2-3 miles of driving the engine stops, if you clear code 0x1190 while driving the engine starts back again, if you go after 4000 rpm the engine won't stop any more. Did you have any result with the HP pump ? Quote Link to comment Share on other sites More sharing options...
d-9 Posted November 28, 2019 Share Posted November 28, 2019 2 months later - freelander is still working fine. High pressure pump has solved the issue, was £200 for a refurb pump. 1 Quote Link to comment Share on other sites More sharing options...
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