I fitted a 2.5 Na in to my series 3 LWB about 20 years since and no major problems but has been stood for a while and other than turning her over every few months has not been used. When laid up ran ok . But did lend her to a friend who had a few problem with her not running. fitted a new fuel filter and this sorted the problem but then she has sat for a while .

Trying to get her running again and back on the road as my daughter wants to use her as her wedding car. Put new fuel in and batteries and she fired up with a little bit of encouragement. she idles but if you push the throttle nothing happens almost as though not connected.
I have pressure through the system and up to the injectors but cant get her to rev. Fitted a new fuel lift pump as could not get this to prime by hand and as only £20 thought would not be to much to loose if not the problem after a couple of hours removing and refitting and priming the system she will fire and tick over nicely but wont rev at all.
Anyone got any suggestions as I am stumped.

This could be the same problem as talked about here:
https://www.landyzone.co.uk/land-rover/2-5-n-a-in-series-3-lacks-power.331032/

Thanks have read through. Some bits helpful.but not all. It will start with no throttle input and no matter what position the pedals is at makes no difference to rpm.almost as though not connected. Confirmed it IS though. Is it possible for the engine into tick over but the internal throttle be jammed?

Acceleration is by increasing the fuel to the injectors sounds like the internals of the pump are sticking , how long have you left it running on tickover?
Let it get fully warmed up and gently tap on the end of injection pump where the HP pipes come out to see if that helps. Think the other threads suggest trying some petrol into Injection pump.

Thanks for that. Will give that a go. Funny was watching an old film where a young women running a garage in the States was fixing a car with a hammer to the engine. Remember telling my kids that you won't fix much with a hammer. How wrong will I be if this works.

Have got it as hot as it can get and given the injector pump a few wacks with the hammer with both throttle in closed and full open position with no change at all. I have taken a small video to show what is happening or not as the case may be. Hope someone is able to give me any other suggestions before having to take to the garage.

Odds are either the governor weights are stuck solid or the collar / metering sleeve which controls plunger travel is jammed.

Taking the pump off for stripping and reconditioning would be the sensible option, but if you're up for some cocking about you might be able to free it off with some luck and solvents. Leave the hammer in the drawer methinks

Beforehand I'd run the engine at idle a good few hours while massaging at the throttle with a heat gun pointed at the pump (or heated fuel supply) the whole time, occasionally pinching at the return line as well can introduce a small amount of extra pressure into the pump to boot. It sounds close to freeing in the video (occasional warble), so this is worth a go unless you already have for the full duration. Try the following if no luck:

Please note - the following may well finish off the internal seals in the pump

Grab a jerry can, and then rig up a supply line and return, put a hand primer in the feed line to save time priming the feed line + pump (can be had off ebay cheap) - now you can easily add or flush various chemicals. I'd start with petrol mixed with a light oil, such as ATF around 50/50 blend, preferably use a high detergent modern ATF for this. Use the primer bulb to fill the pump - you'll want to remove the injector lines for this part. Keep priming and turning the engine over with the starter until your concoction is being delivered, then let it sit overnight (or longer).

Next, you now want to flush the pump through with diesel - place a jug to catch the expelled mixture. Repeat the above, until fresh diesel has been being delivered for a good 10 seconds or so - if you can run the expelled mixture through a coffee filter, the grit that is collected can tell you a lot about the inside of the pump (lots of rust = pump is not long for this world / lots of varnished smeg = old diesel has been left in it and all may yet be well).

Work the throttle a few times, and start her up, odds are no change will occur for a few minutes - but if you can even get a tiny wobble in the revs working the throttle after a time, you're on the right track for success.

Cheers mate. Will give e this a go.