Freelander 1 1.8 won't start - P0340 Code

Hi all. I'm after some help. I have a 51 plate Freelander 1.8 Petrol K-Series which won't start.
The problem started a while ago when I noticed after several motorway drives that the engine idle seemed lumpy with excessive vibration. I initially thought worn engine mounts so changed them and they were worn. Whilst the vibration eased a little it was still present. I pulled the plugs and gave them a clean. But the it became weak on power going up inclines and when accelerating and the vibration remained.
I used an OBDII code reader which came up with P0340 Camshaft Sensor. So I changed the sensor. No change. I changed the wire from the sensor. No change. I changed the camshafts (had planned to change them anyway due to an oil leak from the seals and everything is lined up as it should be including cam sprocket studs). No change. I changed the crankshaft sensor. This time there was a change. The car just would not start. I've tried 3 camshaft sensors and 3 crankshafts sensors. No change. I changed the in-tank fuel pump. No change.
The car will start from cold but runs lumpy. After a couple of minutes switch it off and it won't start again. It turns over but won't fire up.
I've got good spark. So I'm at a loss. I'm not good with electrics and don't have a volt meter. I'm close to scrapping it but can't afford to buy another car right now.
Can anyone offer any help other than setting fire to it???

Could it be injectors or the fuel cut off switch?

Also, and I don't know whether it might be connected but my in-car radio and the car alarm started playing up. The radio would sometimes come on and sometimes wouldn't and couldn't be operated using the buttons. The alarm would sometimes go off randomly. Whilst I changed sensors and stuff I cleaned 3 earthing points that I could find under the bonnet and charged the battery. Don't know if that means anything to the running problem?

First off, put back the original sensors.
You can get in the situation where you change so much, identifying a faulty replacement becomes impossible.
Only use genuine Bosch replacement sensors, as aftermarket sensors are often rubbish.
If you don't have a meter, buy one.
You can get a perfectly acceptable digital multi meter (DMM) for under £15 from Amazon.
When were the plugs last replaced? They only have a limited life, and must be of the correct platinum type, or they last no time at all.
Unstable idling is often down to spark issues, so plugs, coils, leads and so on.
Also check for vacuum leaks around the MAP sensor, and see if you can hear the brake booster hissing from inside the vehicle, near the pedals. A split brake booster diaphragm will cause a week mixture, making the idle unstable.

Thanks for the advice. I'll look at the things you've mentioned.
To be fair coils and leads were changed a while ago. Can't remember when the plugs were changed. But they are getting a spark.
If I find the fault I'll out details on here.
Thanks

Hi again.
Right. Changed coils, plugs and leads. No joy. Changed the other sensors back to the original ones one at a time. No joy.
Not sure how to check for vacuum leaks around MAP sensor. It seems fine. Can't check for leaks near the brake pedals as it doesn't run up long enough to check.
Next step scrappers which is a shame but I'm wasting too much time on it now!

PK68 said:

Next step scrappers which is a shame but I'm wasting too much time on it now!

Click to expand...

Stick it on Ebay, they getting good money, even if not working.