1998 discovery. Replaced fuel pump, crank shaft sensor, battery is good, had tune -up. Driving on highway and car just loses engine power, still have radio, lights, etc. Pull over and start it right back up. Drive about 15 minutes more and it happens again. Starts again. Then it does it again, but now won’t start. Clicking sound in dash on passenger side. I leave it sit for 2 days. Starts right up, then rpms start revving then stops and dies. I have had every diagnostic known run, no codes coming up. I have had local mechanic keep it for days to drive it. He is also at a loss. I am REALLY tired of replacing random parts to no avail. Not to mention the $$ I have spent. Can someone please help.
Sometimes something simple could cause a bit of trouble (granted, nothing is simple in a LR). I will start with checking the ground cable at both ends, then recheck all wiring and cables, look for something loose.
Let’s have a bit more information. 1998 was when Discoverys changed.
Do you have a Discovery 1 or a Discovery II (2)?
Petrol or Diesel?
What engine and gearbox does it have?
LHD or RHD?
When you say ‘it loses engine power’ do you mean the engine stops running?
As an aside, you could get your patients to get out and push 
I had the same problem with my 98 disco, the honest british trained mechanic that fixed it provided me with this explanation, crank sensor need replacement. cost me about $200 part & labour, hope this is helpful.
OP said the pump and crank sensor was replaced already. If battery is good and clicking, I would check connections and ground wires. Alternator problem draining battery and confusing computer? I dunno. If the mechanics can’t figure it out though.
Reminds me of why the British drink warm beer . . . Having a Land Rover should be seen as an adventure though not as a means of reliable transportation. Might be a time to re-assess and trade.
well… if it was a ford I would say electronic ignition box. they can cause all sorts of hard to diagnose problems, and should be tested 4 or 5 times because they often test as good. i have no idea if your truck has anything similar
Lets start with simple all battery and ground connections cleaned. Ignition key does not have a bunch of stuff hanging from it. Alternator is good and putting out clean DC power at 14.5 volts. Are all the spark plug wires new. One could short intermittently to the block and kill the ignition. Are there any codes? There is the ECM, Multifunction Relay Unit, Anti-Theft and the coil pack. Any one of these could cause the engine to turn off. Coil pack can be ohm checked, but heat can cause them to fail.
“Starts right up, then rpms start revving then stops and dies.”
Your symptoms, particularly the one quoted above, seem to me to be typical of a fuel metering problem. Generally those can be isolated to either a vacuum leak, a bad sensor, or a bad metering system (such as the IAC or throttle body…since it’s dying while driving, I’d move the IAC to the very bottom of the list of contenders.
I admit to not knowing a lot about Landies. However, I believe you have a cam position sensor in addition to your crank speed sensor. The cam sensor would tell the ECU what position the valvetrain is in and the ECU would use that input to activate the multiport injectors. Or, if it’s flakey, NOT fire the injectors. While I’d expect a bad sensor to post a fault code, I’d wtill consider it a possibility.
One other possibility I’d consider is the inertia sensor, whose job is to kill power to the fuel pump in the event of a crash. If it’s located behind the dash, it mght be that the clicking is its clue.
I wish I could do better than offer some generic ideas, but if I think of something else I’ll post.