Land Rover Discovery (series 1) V8 unreliability
Over the last fifty years, there have been few occasions when one of our vehicles has broken down or had a puncture. We had a Ford Sierra which when it was about nine years old spluttered and conked out on occasion - then would restart about 10 minutes later. Tried various things before taking to a garage where mechanics had met this problem before - the filter over the fuel pick up pipe in the petrol tank had collapsed.
Some years earlier our Land Rover 2 1/4 Diesel conked out on way home from work - a spring had broken in a fuel injector so that the piston forced air into the fuel injection pump.
Later we bought a secondhand Petrol Automatic Land Rover Discovery Series I (see above).
The Discovery was a joy to drive, but there was a spell, as it got older when very occasionally it would not start and finally one day conked out. The primary cause was an intermittent fault with the fuel injection system relay; cheap and easy to fix once the problem was identified.
Poor connections in the alarm spider module also caused occasional non starts; a well known fault which the garage eventually fixed by bypassing the module.
Hopefully the following tips may be of some help to owners of ancient V8 vehicles experiencing similar problems.
Spider Related Problems
1) Starter occasionally fails to operate - caused by dry joint on immobiliser Spider PCB which is awkwardly located below the radio/cassette. To get at the unit you need to dismantle the dashboard - a job you probably don't want to do yourself!
Tip - just possibly tapping top of dashboard may get you started; get main dealer either to replace the Spider AMR 4889 or by-pass the unit.
2) Slight burning smell, vehicle conks out, no spark - possibly caused by bad joint on Spider PCB
Tip - you may be done for; phone breakdown service for low loader to take you to main dealer.
One might think relay coils never go wrong; but they do and can occasionally go open circuit, so that for example the fuel injection system and/or fuel pump are disabled.
3) Engine turns over but will not start because either the fuel pump does not run, due to a faulty relay, or the fuel injection relay is faulty.
Tip - when the ignition is switched on listen; you should hear a click from the foot-well as both the fuel pump and fuel injection system relays switch on, followed by a buzz or brrr from the fuel pump for two seconds, followed by a click as the fuel pump relay switches off.
If you do not hear the relays click on and then off replace both the fuel pump relay and the fuel injection system relay (part number AFU2913L). These are only about £15 each. It is a good idea to replace both relays, in any event, if you are having problems with the fuel pump.
You will need to remove the driver foot-well panel (see Haynes manual). The relays have a silver metal top and clip into black (system) and blue (fuel pump) holders. Pull relays complete with holder up off metal lug, then using screwdriver lever relays from holder.
If the relays click and the fuel pump does not run, the causes, in order of likelyhood could either be a,
To access the fuel pump, under load space, unscrew plastic trim, then remove rubber mat, carpet and peel back underlay. Then unscrew and remove fuel pump cover plate from load space floor.
To remove the fuel pump connector, squeeze end of plug and pull off.
With meter, check 12 volts reaches the fuel pump on the purple/white wire. You will need helper to turn on the ignition as the 12V is only present for two seconds (see above).
Spray plug with contact cleaner, if available, and push plug on and off a few times.
As petrol is highly inflammable, replacement of the fuel pump, if needed, is best done by a main dealer (cost about £200). It might be a good idea to ask the garage to replace the fuel pump connector at the same time if it comes with the pump and is not sold separately.
5) Over weeks, the alarm system can significantly drain the battery if the vehicle is not used regularly. This will considerably reduce the life of the battery and its capability to hold a charge.
Tip - trickle charge the battery once a month if you use the vehicle infrequently.
Whatever vehicle you drive always be prepared to cope with an accident or breakdown,
Disclaimer - these tips are for information only. Always seek professional advice from a competent person.
Last updated 30th April 2021