Difficult to start and then stops when idling

I thought I would give this a new thread as a couple of previous inputs were caught-up with another, which I didn't want to hijack...
So.. I have a Disco 2 Year 2000. The car is very difficult to start, when you eventually get it going it doesn't seem that smooth and if you let it idle for more than 5 minutes, it will suddenly run very rough and stop.
Additionally when you start the car you hear air purging through the pump/system. Here's what has already been looked at..
Fuel pump - replaced
Fuel filter - replaced
Non return valve - checked and doesn't appear to be stuck
Injector o-rings & washers - replaced
This shows no errors when running a nanocom and taking a live download of the fuelling inputs doesn't show anything obvious, stats appear steady until the engine dies.
The pressure regulator was replaced about 1 year ago as the previous one was leaking. I'm running out of ideas on this one .. Any assistance would be welcome.. And thanks for the inputs to-date

KMAS100 said:

I thought I would give this a new thread as a couple of previous inputs were caught-up with another, which I didn't want to hijack...
So.. I have a Disco 2 Year 2000. The car is very difficult to start, when you eventually get it going it doesn't seem that smooth and if you let it idle for more than 5 minutes, it will suddenly run very rough and stop.
Additionally when you start the car you hear air purging through the pump/system. Here's what has already been looked at..
Fuel pump - replaced
Fuel filter - replaced
Non return valve - checked and doesn't appear to be stuck
Injector o-rings & washers - replaced
This shows no errors when running a nanocom and taking a live download of the fuelling inputs doesn't show anything obvious, stats appear steady until the engine dies.
The pressure regulator was replaced about 1 year ago as the previous one was leaking. I'm running out of ideas on this one .. Any assistance would be welcome.. And thanks for the inputs to-date

Click to expand...

my 1st thought was the injector o rings and washers. Having seen what you have done have you checked/changed the vent on the fuel filter?

Sorry forgot to add that.. Yes I did when I changed the fuel filter

Hi gazman, you suspect this? I did check this non return valve.. Seemed OK, want stuck at all

Ok, tomorrow I'm gonna get a new non-return/bleed valve and a new CKP sensor. I'll post the update tomorrow

KMAS100 said:

Ok, tomorrow I'm gonna get a new non-return/bleed valve and a new CKP sensor. I'll post the update tomorrow

Click to expand...

that sensor is a good ideea to be ruled out ... about the valve, dont mix the non return valve with the air bleed valve cos they are not the same, 2000 model doesnt have non return valve only the air bleed valve(WJN500110) in the rear wheel side connection of the filter head

Thanks Sierrafery, that explains that one for me.. Must admit I didn't know the difference, mine is a small plastic insert with an o-ring on one end. Hoping its th crank sensor as your earlier post to me.. Car is unusable right now!

you must get above 300 reading while cranking but the wave form is important too, the only certain way to rule it out is by replaceing it with new or oscilloscope

I'm no expert, but I've read a few posts about these when I was having problems with mine.
But at £9 it's not going to break the bank to find out

Are you sure it's not an injector nozzle leaking compression gases into the fuel system, crankshaft sensor won't put air in system

Latest update - problem resolved! ( I hope).
Ok, so today I bought a new crank sensor and another new fuel water filter, the local supplier here in sunny Cyprus didn't have the air bleed valve..... So, after changing the crankshaft sensor (which took about 5 minutes) the car immediately started !!! Lots of great cheer and happiness!.... Turned it on and off several times and started immediately everytime. However, after leaving it ticking-over for about 10 minutes it displayed the same symptoms.. Knocking noise, uneven running and then stopped!
At this point I changed the fuel water filter and and tried again... Nothing, wouldn't start even after a purge. Then I thought I would take a look at the air bleed valve again, seemed fine.. Cleaned it etc and it had a good seal via the o-ring within the connector.. Thought to myself, 'what harm can it do to take it out and run it without it?' After all I get air purging everytime I start it anyway.
Took it out, purged the air once and the car started, running smoothly, starts everytime, etc etc. Happy days!! What's more, the fuel pump noise has disappeared too.
Well I'll order a new one from the UK but I'm running the car without it right now.. Seems fine!
Thanks for everyone's assistance, particular thanks to Sierrafery and Gazman.. And I'm assuming plenty of "I told you so's...." are rightly in order.

Told you so ... and welcome, i'm glad this wasn't in vain