p38 missfire

just sorted out the audio had new clarion fitted works fine but as we were sat on tickover learning how to use new toy lol the engine just cought a little then about 2 mins latter done the same this lasted for about the 10 mins it took to explain new toy the car never stalled and was fine driving home put it through its paces a little see if i could notice anything not quit right but all seemed fine got home let it tickover and still coughted ever 2 mins or so any ideas please? deisel 2.5 btw

Drawing in air somewhere. My money is on the tank pump. How much fuel was in it?

just under half a tank it seems fine when going on a run but sat in traffic later today was coughing again

I had the same on my 2.5 DSE turned out to be the (in tank) fuel pump.
BUT... six months later I have similar problem and it has got worse and will now cut out on tickover (only occasionally), sometime not start at all (occasionally) and do the "misfire" bit when running. I am taking it tomorrow to a local P38 specialist (or so I was recommended - hope it's true). The bottom line is it could be caused many things, so you need diagnostics to find the fault. I don't believe this mean a LR dealer who will probably run Testbook & diagnose a faulty expensive component. But also someone who understands to fix it, e.g. in my case after replacing many parts as advised by local garages I decided to buy a Faultmate. This tells me I have an incorrect value on high wire from engine speed sensor. But of course this does not mean the sensor is actually fault, just that this is what the ECU is receiving. So with a bit of luck my recommended specialist will be just that and will get to the bottom of it. Sorry to say for you that this is in Swindon, but I'll let you know how I get on anyway, it may help.