Landlover99
Active Member
Update: I'm trying to get through to another bloke I know here - the one who helped me out with the drop-arm saga of last year - he's also a Deffie owner and may have, or have access to, a scanner....
In the mean time, the rain's finally stopped, so I'm off outside to chase down the crank sensor...
In the mean time, the rain's finally stopped, so I'm off outside to chase down the crank sensor...
Landlover99
Active Member
Well, the aforementioned bloke didn't turn out to be of any help. His Deffie is an old pre-ECU one and although he's a mechanic he doesn't know anyone with a portable scanner/code reader.
I have carried out a few more tests in the mean time. The ECU is grounded and has +V supply to it with the ignition switch on. The crank sensor appears to be in place so far as I can tell and from measuring the continuity to it from the ECU plug, it's showing as connected up properly and the sensor's resistance is 1.2k ohms. So unless that figure is out of spec (it may be of course, I'll have to check unless someone here knows) there appears to be nowt wrong with it.
I'd really like to be able to probe the ECU lines with an oscilloscope; it would quickly provide valuable clues as to the fault, but I cannot get probes into the sockets; they're so well shrowded and it's not feasible to probe with either the red or black plugs unplugged because quite probably that would prevent the unit from functioning, anyway.
Any final suggestions before I throw in the towel and get it towed in for pro-diagnostics?
I have carried out a few more tests in the mean time. The ECU is grounded and has +V supply to it with the ignition switch on. The crank sensor appears to be in place so far as I can tell and from measuring the continuity to it from the ECU plug, it's showing as connected up properly and the sensor's resistance is 1.2k ohms. So unless that figure is out of spec (it may be of course, I'll have to check unless someone here knows) there appears to be nowt wrong with it.
I'd really like to be able to probe the ECU lines with an oscilloscope; it would quickly provide valuable clues as to the fault, but I cannot get probes into the sockets; they're so well shrowded and it's not feasible to probe with either the red or black plugs unplugged because quite probably that would prevent the unit from functioning, anyway.
Any final suggestions before I throw in the towel and get it towed in for pro-diagnostics?
Have you completely ruled our fuelling issues? Given your background you seem to be focussing on the ecu, a black art in itself. I did ask before about the fuel pump and you said you could hear it running. Have you tried disconnecting the fuel line as it goes into the fpr then momentarily switching on the ignition? You should get a very strong flow of fuel. If you can block the flow with your finger, then no chance it will start. (Even better if you can connect a pressure gauge! )
sierrafery
Well-Known Member
insert thin needles from behind in the ECM connector while it's connected as to reach the pins and check with oscilloscope the crank signal on it's wiring... you should get 2-3V sinewave while cranking depends on how fast it turns...i dont remember the amplitude or frequency but the voltage is important...though according to the resistance the sensor seems good: http://www.landyzone.co.uk/lz/f50/td5-engine-does-not-start-after-flywheel-replacement-224429.html
you really need to rule out an ECM internal fault as ''topside switch failure'' or ''checksum error'' with a proper tester
you really need to rule out an ECM internal fault as ''topside switch failure'' or ''checksum error'' with a proper tester
Landlover99
Active Member
I admit I've been focusing on the electrics, because it presented as an electrical rather than a fuel problem inasmuch as the engine just instantly died without any preamble; it was just as if a swich had been turned off.
Nevertheless, I would like to carry out the test you suggest. What and whereabouts is this "fpr" you mention?
I also cannot see the actuation wires for the injectors, which I'd like to test for the presence of correct impulses.
Landlover99
Active Member
Thanks for that, Sierrafery. I'll give it a go tomorrow if time permits.
It's a pity I don't know anyone here who could lend me a known working ECU from their own vehicle to rule that possibility in or out.
sierrafery
Well-Known Member
you can't do that either without proper tester cos it needs immobiliser code syncronisation.
It's a pity I don't know anyone here who could lend me a known working ECU from their own vehicle to rule that possibility in or out.
if you have the diagrams you can check injector impulses at the plug which is connected to the injector loom in front of the engine under the rocker cover.... it would be a good test to rule out the ECM cos if the injectors dont get signal that's it... i attach you the relevant pics if you dont have RAVE
Landlover99
Active Member
Oh! I didn't think about that security issue. Bugger!
I burned the CD you pointed me to but haven't been able to view it yet as it's Windows-based and I'm a Linux user. I do have a Windows pc but it's not in general use.
If you have the pix, that would be great.
FPR is the fuel pressure regulator. You will find it at the rear lhs of the engine, just below the rocker cover. There are two pipes on quick release catches (that's a misnomer if ever there was!). One of these pipes comes direct from the fuel pump in the tank. The other goes to the fuel cooler. Disconnect the feed from the tank and test the pressure there, either by gauge or holding back pressure with finger.
sierrafery
Well-Known Member
better do somehow to open that RAVE cos i can't attach it here but for now, i hope that you can read PDFs with linux though so download this http://www.landroverweb.com/Pdf-files/Defender MY2002 Wiring Diagram.pdf go to engine management you'll see how the connection is, then see attachments and if you know electronics you'll figure it out...good luck
Attachments
Landlover99
Active Member
Thanks for that info, Derek. Just a bit concerned about testing the pressure with a thumb over the pipe: is that kosher pressure-wise? I mean, I don't want to end up getting diesel in my bloodstream (which I seem to recall was some sort of horror story I used to hear from diesel fitters way back in the 70s...)
Landlover99
Active Member
I've just remembered I have a fully working Windows image I should be able to boot from on a spare laptop partition so it won't be a problem, thankfully!
OK, that should do it for the time being. I'll report back in due course!
Would be so nice to get this fixed without having to go crawling to those vultures at the main dealership.
MJI
Well-Known Member
Points, horrible things, carbs a nightmare.
There speaks someone too young to ever know the joy of teasing a cigarette paper from between clenched points and measuring their release BTDC on a protractor.
Someone who had a bike whose points wre a nightmare.
Someone who had a 1978 car with electronic ignition
Landrover ownership often involves getting covered in oil and/or diesel! If this is a problem, rubber gloves/ protective clothing can be worn!
I only suggest you explore the fueling issue as it happened to me exactly as you describe. Turned out to be the fuel pump which does have a couple of filters within it's housing.
I only suggest you explore the fueling issue as it happened to me exactly as you describe. Turned out to be the fuel pump which does have a couple of filters within it's housing.
Landlover99
Active Member
I will do. I was just concerned about the very high pressures involved here (200atm IIRC) not about getting some diesel over me!
I've just noticed there's a thin black ground wire hiding behind the blue/white and black/pink pair, so this is an active 3 wire system and not the passive 2 wire type I'd previously thought. Moreover, there's about 20mm of insulation missing from the ground wire just as it disappears into the loom! Looks like it's been pulled by something cos it's kinked but there's nothing moveable in the area to account for it.
So my testing thus far is incomplete. I need to establish the sensor is actually grounded, otherwise of course it cannot work. First job tomorrow, that'll be.
Landlover99
Active Member
Cheers for that. Much better diagrams than the ones in my Haynes manual!
Landlover99
Active Member
Hmm. Not sure about that ground wire. Might just be a shield. Bit more investigation required. Anyway, enough for today. Til the morrow, friends!
v8landyman
Active Member
The pressure from the fuel pump is not that high. It's the injectors themselves that develop the very high pressure when in operation.
Couple of other things that no one has mentioned yet.
Don't forget oil in the injector loom problem. Usually this just results in poor running, but can make the engine cut out, as happened to me. You can see oil in the multiplug where the injector loom enters the engine. It is at the front of the engine on the driver's side just under the rocker cover. Or, if it's been leaking for a long time, it might have crept all the way back to the red plug of the ECU under the driver's seat.
The condition of the wiring loom itself. Land Rover seemed to have some bad luck with the quality of its wires in the mid 2000s. The insulation is prone to flake off and chafe, and the conductors are brittle and apt to break. This leads to all kinds of peculiar, hard to diagnose faults. I had something similar to the OPs problems earlier this year and ended up getting a new wiring loom, which is much more supple.
The best course of action is to have a look at the output from a dedicated TD5 fault code reader (I prefer the Nanocom myself). This can give you some useful information. For example, when you're cranking the engine, can it tell you the engine revs? Can it tell you cylinder balance values? If so, it suggests the ECU is getting a good signal from the crank position sensor.
Don't forget oil in the injector loom problem. Usually this just results in poor running, but can make the engine cut out, as happened to me. You can see oil in the multiplug where the injector loom enters the engine. It is at the front of the engine on the driver's side just under the rocker cover. Or, if it's been leaking for a long time, it might have crept all the way back to the red plug of the ECU under the driver's seat.
The condition of the wiring loom itself. Land Rover seemed to have some bad luck with the quality of its wires in the mid 2000s. The insulation is prone to flake off and chafe, and the conductors are brittle and apt to break. This leads to all kinds of peculiar, hard to diagnose faults. I had something similar to the OPs problems earlier this year and ended up getting a new wiring loom, which is much more supple.
The best course of action is to have a look at the output from a dedicated TD5 fault code reader (I prefer the Nanocom myself). This can give you some useful information. For example, when you're cranking the engine, can it tell you the engine revs? Can it tell you cylinder balance values? If so, it suggests the ECU is getting a good signal from the crank position sensor.
