disco problems

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jandhooge

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Hello there LR-fanatics. My name is Jan, I am a car mechanic from Belgium so it may be possible my english writing is not so good.
I'm driving LR Discovery now for about 18 years, but now I've got a problem with my Disco II '99. The engine just stopped while driving and it didnt start again.
I have checked fuel pump, renewed injector wiring, checked the wiring off the Motor Control Unit(MCU) because I didn't measure the 70 volt tension on the injector connections. I have changed the fuse box inside and the one in the motor compartment with the one from my other Disco (year 2001) but nothing helps. I have tried some trics to enable the transponder and finally changed the MCU for an other one and went to the dealer to match it with the car.
This dindnt help eather, the engine cranks fine, no faults are recognised by the MCU but it just wont start.
So now I'm hoping somewone of the land of Land Rover can help me.
Thanks:mad2
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Hi,
1. how did you check the pump? ..did you actually measure the pressure? if not improvise a gauge with a fitting as to be able to screw it instead of the fuel temp sensor in the FPR and see if you have 4 Bar there...there's no other certain way to "check" the pump/fuel delivery to injectors...you must be certain that the 4 bar gets there...i presume you ruled out a clogged fuel filter didnt you?, is the pump noisy when you turn ignition on?

2. try with a new/known good crank sensor...check well the wiring/plug of that one

3. replace injector washers/seals

make sure the ECM(MCU as you named it) has'nt lost the earth...there is an earth rail under the battery cover with 3 nuts check to not be loosen
 
Hello; thanks for the reply but all the things you prepose I have already checked and made sure the earth connections are clean; pressure is good and ckp was changed. There is no voltage on the injectors but why? I was told there is a little green CPU in the back of the instrumentpanel that can cause ECM closing down. Dit not have the chanse to check it, do you now what it is and what its for?
 
jandhooge said:
Hello there LR-fanatics. My name is Jan, I am a car mechanic from Belgium so it may be possible my english writing is not so good.
I'm driving LR Discovery now for about 18 years, but now I've got a problem with my Disco II '99. The engine just stopped while driving and it didnt start again.
I have checked fuel pump, renewed injector wiring, checked the wiring off the Motor Control Unit(MCU) because I didn't measure the 70 volt tension on the injector connections. I have changed the fuse box inside and the one in the motor compartment with the one from my other Disco (year 2001) but nothing helps. I have tried some trics to enable the transponder and finally changed the MCU for an other one and went to the dealer to match it with the car.
This dindnt help eather, the engine cranks fine, no faults are recognised by the MCU but it just wont start.
So now I'm hoping somewone of the land of Land Rover can help me.
Thanks:mad2
progress.gif
Click to expand...

A friend of mine had the same problem as you. A long shot here, but check the condition of the fuel filter housing. If it's showing signs of corrosion, it could be letting air in.
 
jandhooge said:
Hello; thanks for the reply but all the things you prepose I have already checked and made sure the earth connections are clean; pressure is good and ckp was changed. There is no voltage on the injectors but why? I was told there is a little green CPU in the back of the instrumentpanel that can cause ECM closing down. Dit not have the chanse to check it, do you now what it is and what its for?
Click to expand...

did you use an oscilloscope to check for voltage on the injectors? ...cos you'll not see anything with a multimeter, it's a pulsatory voltage...and where did you measure, at the ECM plug or on the injectors?

IMO who said about that "little green CPU" meant an immobiliser ECU which is on D1, not the case for D2
 
I have compared the measurments with my other disco. I measured with a multimeter on AC(acvtive current) , then you can measure the pulse.
If I understand I better not look for the green box.
 
it's no green box on a Td5, you have to make sure the ECM gets the feed... unplug and bypass the inertia switch, maybe it's on that circuit...measure for all the feeds to be present at the ECM...do you hear the pump running when you turn ignition to II?

i ask again where did you measure for voltage, at ECM red plug?... cos if not you better check there cos i saw cases when the wiring from ECM to injectors was chaffed
 
I measured on the red plug and on the connector of the injectorharnes. Pump was renewed 6 months ago and works fine. diesel filter was changed at the same time.
Could it be the body computer is broken? The LR-dealer disabled the immobilizer but this didnt change a thing. Maybe it is not even listening to the software of the dealer.
 
the immobiliser wouldn't let it crank neither... I have some doubts now that the dealer 'matched' well that ECM cos if they didn't it won't start as it must learn the security code from the BCU or it won't fire the injectors... I'm wondering why did they let you unsolved anyway.... schmucks

by the way, did you check if the crank signal reaches the ECM?...there must be 2-3V AC while cranking
 
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The crank signal is fine measuring as monitoring with my computersoftware.
Today had somebody who ownes a nanocom but didnt find any foults.
He tried to reprogram the BCU but this didnt work because he needed some entry codes.
Does anyone know where a can get those. Thanks
 
IMO not the BCU is the problem as long as it cranks...enter in engine management - programming - learn security code and it will learn it alone... as long as this engine didnt run at all or the ECM is in a "secure" status it will not store fault codes.... try on the working car the ECM which which was on this car when it stopped... you must just make it learn the security code of the other one cos it will run at idle without coding injectors...if that ECM works on the other car IMO there's an interruption in the engine harness somewhere
 
not with non-programmed just with not coded injectors... you must make the ECM to learn the security code from BCU to run, the injectors must be coded to run well at high revs so just to test the ECM not necessary

so to make the engine fire up you must sync the ECM with the BCU security code and set the driver demand(2 or 3 way throttle)... it's not necessary to set injectors to make it run at idle
 
by the way measure battery voltage while cranking...if it fails under 10V it will not start as the starter leaves the the ECM without power ...the Td5 is not like other cars it can crank for long but not start if the battery is not fully charged...and powerfull too, tou must have above at least 10.5V while cranking...the more the best
 
The problem is not the injectors, its the power they receive from the ECM, I can hear the injectors when powered with nanocom, all five are clicking but when I turn the key nothing happens.
 
Sorry for misunderstanding but the nanocom is no longer here so I cant trie the things you prepose. I have ordered a nanocom myself, i expect it by tuesday so i'll have to wait till then. I will post again when I tried your preposal. Many thanks. Jan
 
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