Disco 1 Edc problems

I've written about this before where a common problem with later D1 autos is that the diesel doesn't get to the injectors and all other fuel tests are OK. All the threads I've seen have gone dead or the injectors and pump have been replaced by parts from a manual, or the vehicles were scrapped.
To me there should be a solution, are there any electronic or electrical experts out there who could find a method to bypass the immobiliser circuit which seems to be the most likely culprit. Obviously there's a security issue on an open forum, but I've two of these vehicles, one which has that problem intermittently. I suppose a fault no 4 injector might cause a similar issue, i really don't know. Mine never gave a code.

Yes you can bypass the D1s immobiliser its simples if you have the skill to do it.
The immobiliser only inhibits two vehicle systems and either can be faulty, so thats the starter so cranking, and the fuel petrol or diesel into the engine.
Faulty diesel fuel injection i don't know either, i don't do diesel.



Sent from my iPad on a train.

As I understand immobiliser is quite easily bypassed on most 300tdi manuals. On later ones, I think there are connections on the pump which can be altered.
Later autos are different, this is the problem I'm referring to.

If you suspect it could be the No4 injector why not try swapping them over from one car to the other and see what happens, you never know. If it does turn out to be your problem I could let you have one of my two spare ones.

When #4 injector let go, and I was quoted £1K+ to "make" a new one, I took the EDC off, and have never looked back.
A FWIC and tuned FIP have given me 146 Hp, which is plenty for the 4HP22 to be dealing with IMHO, even with short period oil changes.

Diagnostics of the period were one of the reasons I was against spending daft money on an injector, they are very poor IME, and I decided to remove this complication...

All I can really say about the immobiliser is that the wiring diags in RAVE are something of an acquired taste, and it seems we must acquire said taste to be able to resolve these issues..

I intend to keep my D1 for ever, and it'll get fixed no matter the cost .....

Main issue is that it's intermittent in my case and it only occurs after a lot of stop/start use. I haven't been able to replicate it recently. After a few days it will start and run normally. This Disco has now been sold for breaking but I'm getting the pump, injectors and immobiliser ecu back.
I'm thinking about the future for my good Disco as whatever the problem is, it kills a lot of good autos.

Kenbo said:

As I understand immobiliser is quite easily bypassed on most 300tdi manuals. On later ones, I think there are connections on the pump which can be altered.
Later autos are different, this is the problem I'm referring to.

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Correct, as from the 1996MY D1 the 300Tdi was fitted with electronic diesel control (EDC) which is now also used to carry out the immobiliser function, it appears to be more reliable then the previous ‘spider’ item, the two items inhibited are still the same when the vehicle is immobilised.

If you can crank the engine? then all that is left is a wiring modification to the item that supples diesel to the engine as you state. The wiring is no secret, the mod you required it been mentioned many times in LR Forums.

The bottom line is ensure that it is an immobiliser issue first, and not another item that your D1 uses in fuelling.

Engine always cranks, good diesel supply to the injector pump but no further. I've looked extensively on all the edc threads, never seen a wiring mod for edc, plenty for non edc. Am I missing something?

Kenbo said:

Engine always cranks, good diesel supply to the injector pump but no further. I've looked extensively on all the edc threads, never seen a wiring mod for edc, plenty for non edc. Am I missing something?

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Forgive me for my over-simplistic simplicity, but could it be something as simple as a stop solenoid not functioning?
If diesel is getting to the injector pump but not beyond it could simply be that the solenoid isn't working. In which case take it out, put the whole thing back together without it again and see if it starts. (Mind you it'd be worth taking a positive lead to it first to see if it clicks or not. If it does then the fault is in the wiring or EDC which governs it.
You'd need a way of stopping it though, like a tap in the diesel line, else it could just run and run, unlike a manual where you could just stall it. (Do realise the lack of electric to the pump may stop it in the end!)
Had this problem with another small diesel, thought it was the immobiliser but it wasn't. Using the stop solenoid as an immobiliser is common on a lot of diesels, or it used to be.

Do totally realise the EDC may run things entirely differently in which case I will instruct my ass to shut up!

Kenbo said:

Main issue is that it's intermittent in my case and it only occurs after a lot of stop/start use. I haven't been able to replicate it recently. After a few days it will start and run normally. This Disco has now been sold for breaking but I'm getting the pump, injectors and immobiliser ecu back.
I'm thinking about the future for my good Disco as whatever the problem is, it kills a lot of good autos.

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Well if your “stop/start use” is as stuck in traffic, then its not unheard of for a fuel injection engines temperature sensor to play up, as an example stop in traffic the engine temp rises and the engine starts misfiring and possibly stop, but get moving again and the issue clears, its some thing I’ve had with a couple of cars I’ve driven in the past.

Stanley; stop solenoid innards have already been removed, not needed on the edc.
Stop/start has always been for occasional maintenance on a farm, just a few times a month but since this first happened, I haven't been able to rely on it.
Recently I've just keep the engine running for the few hours I need it. I still reckon the problem is in the immobiliser circuit but no one seems to have the knowledge to bypass it, and I certainly don't. As I've said, this seems a common enough issue on the edc system.

Thanks so far for the comments.

Kenbo said:

Stanley; stop solenoid innards have already been removed, not needed on the edc.
Stop/start has always been for occasional maintenance on a farm, just a few times a month but since this first happened, I haven't been able to rely on it.
Recently I've just keep the engine running for the few hours I need it. I still reckon the problem is in the immobiliser circuit but no one seems to have the knowledge to bypass it, and I certainly don't. As I've said, this seems a common enough issue on the edc system.

Thanks so far for the comments.

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I did think it was a bit too simple!
I am sorry I cannot help you further. Electronix is more or less beyond me.
If it was me I'd just chuck the whole feckin lot in the bin and go for the same fuel injection system as there is on the manuals. Far simpler and easier to fix/understand.
One fine day some clever bugre will find the dodgy joint/component on a pcb somewhere that needs a simple fix, but until then we are all bugred!

After thinking this through a bit, as it is intermittent, I'm wondering if you haven't just got a wire somewhere that shorts to earth from time to time, i.e. chafed through?
Does it happen more in damp conditions?
Can you follow the loom all the way back to the EDC from the injection pump?
Failing that I am wondering if you have a dry joint on a pcb in the EDC. or again a faulty earth.
Finally, is the battery fully up to snuff?
So often that seems to be the problem, that and dodgy connections to the batt and/or earths.

I never really investigated as it always came back to life after a couple of days. Anytime I used it recently, just left it running and that worked for me as it was only used a couple of hours per month. It's sold and off tomorrow to a new extreme off road life, buyer has a manual pump for it. The main purpose of my thread was to see if anyone could work out a method of bypassing the Edc immobiliser.
I'm told Jap imports had the same pump but without an immobiliser, my brother has one so I'll have a closer look at that as an alternative for my 'good' Tdi auto.
Thanks to all.

Kenbo said:

I never really investigated as it always came back to life after a couple of days. Anytime I used it recently, just left it running and that worked for me as it was only used a couple of hours per month. It's sold and off tomorrow to a new extreme off road life, buyer has a manual pump for it. The main purpose of my thread was to see if anyone could work out a method of bypassing the Edc immobiliser.
I'm told Jap imports had the same pump but without an immobiliser, my brother has one so I'll have a closer look at that as an alternative for my 'good' Tdi auto.
Thanks to all.

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Well if you DO find this out from your comparison then that would be a fantastic end to this thread and very useful to others with the problem.

Just another query on this issue: old farm Disco is away but i still have the option of taking off a few more non mechanical bits.
I'm getting the keyfob and the green ecu which lives in the passenger footwells, and I've already got the electric window ecu which was close by. Dash is nice but I don't think it's worth the hassle.
Anything else I should take?