This LRO reader emailed LRO.email@example.com to ask Steve Jones about sorting dead Land Rover Discovery 2 electrics.
I live in rural Australia and have a dead Discovery 2 Td5 automatic. What started as a fairly small problem got much worse after I changed the injector pump to stop diesel running into the sump. After this, fuel seemed to take longer than usual to reach the cylinders, so I installed a fuel pump with a hand primer and pumped fuel through until it was returning via the cooler. The engine continued to turn, but it wouldn’t fire.
Hoping to cure this, I cleaned the crank sensor, removed the injector wiring, blew it through with an airline and hung it in the sun for a day – but there was still no combustion. Next, I checked all the fuses, replaced all the relays, and stood the ECU in the sunlight to get rid of any oil – after which the engine stopped turning. Many days of checking
followed, but they left me with inert engine management circuits in the under-bonnet fusebox. Fuses 22 and 23 (starter and engine) under the dash were also inert, and the red-and-white wire to the ignition switch was dead.
There was power at the fuel cut-off switch, but none at the fuel pump. A starter button bridged to the under-bonnet wire to the starter made the engine turn, but turning the ignition key didn’t. Thinking it might be a faulty transponder, I tried the spare key, but with no success.
A secondhand BCM brought the engine management fuses under the bonnet back to life, but nothing else changed. The only person living near me with a Land Rover Notebook keyed in the BCM, but it made no difference. For about a week before all this trouble started, starting the engine had taken two or three turns of the key.
The nearest Land Rover mechanics are more than 200 miles away, and it would cost me a fortune to get the Disco to them. Any advice you can give would be greatly appreciated.
David Snadden, Australia
You’ve treated your Td5 like a Toyota FJ, and by doing that you’ve destroyed the evidence of what’s wrong with it. Remember – it’s a computer on wheels and needs treating as such. I deduce from what you say that you traced the poor starting problem to fuel leaking into the sump, which you have now cured. However, I don’t think it was a good idea to leave components in the Aussie sun, particularly electronics.
I suggest you try two things initially. First, replace the injector harness with a new one and clean the plug in the ECU with contact cleaner or similar solvent. Next, get the starter working on the key. Make sure you have a live feed (brown) to the back of the ignition switch and that the white and red goes to 12v. You may need to check the wiring to the relay that operates the starter. Also check you have fitted the correct replacement relays. Once you’re at that stage, you should be able to test for possible faults if it still won’t start.
This workshop advice appeared in the November 2015 issue of LRO. Back issues are available to download on digital devices here.