Need some expert advise on my engine.

First post so hello everyone.
I've got a N reg 1995 Discovery ES Auto 2.5 diesel (300tdi?) with a poorly engine.
So many symptoms I'm not sure there all from the same problem! Here are the good bits - starts, idles, and accelerates great.
Now the bad bits - 'check engine' flashes up randomly and engine looses power, if I hit the gas hard the light goes out and away we go, same if I ease off (light goes out and off we go again). There is a misfire if I try to hold a speed, although not so bad on a motorway. When it misfires its like I've taken the keys out for a splt second, no power, even the rev counter drops down to zero and it keeps doing this over and over again with the 'check engine' on for good measure sometimes.
I've had it on test but the garage said the fault didn't show up and that I should think about changing number four injector?....help...please...I don't want to hurt it but....

clean the fuel sedimentor out and change the fuel filter as a matter of course, then report back

ok has it gone to a garage that has the kit to plug in?? its not obd or obd2 software trust me i know.

someone on here may have the kit close by to diagnose it for a beer token or two.

have you serviced it lateley? sounds like a fuleing issue to me try the cheep things fule filter, sedimenter, lift pump.

check fule lines as could be a soft part that constricts under demand had that in a transit.

remove pipes from turbo to intercooler and up to the intake inspect fot internal delaminateing.

clean intercooler

doa the vac pipes from the pump to the egr via valve block have worn lines?

is the egr working ok? if still fitted?

check the turbo is ok

hope this helps a little

Thanks Battenburg, fuel filter will be here and will fit later today, also thought I should probably put an air filter in there too - it didn't have one!

Thanks also to Disco dude, wow loads to look at. Thing is I don't understand half of it! obd / obd2 software - it was a landrover specialist so hoped it was correct but will check. As stated will do fuel filter ect. - just weird that its great under accereration. Not sure what an egr is but will check all vac pipes and ones to the air flow meter.
PS what's the egr???

Thanks.

do the sedimentor as part of the filter change, you will need an 11mm spanner, overalls, eye protection, and an ice cream tub!

sedimentor is inside the chassis rail by the back axle, working blind; undo the top vertical bolt and drop the bowl off. careful not to get a face full of diesel! use and ice cream tub to catch the spill as you drop of the bowl.

if you got a jelly fish living in there, then that's most likely your problem!!!

good luck

use the search to find out about EGR ...loads on here..

oh, and fill your new filter with diesel before you refit. run the engine to make sure you have no airlocks in between doing fuel filter and sedimentor...