looking fo helpful advise
 

96 disco. Checked fuel pressure and only getting 30 psi, is it time to change and will there be any noticeable difference in the way it drives? Thanks in advanced for any help.

Time to change fuel filter, but my 97 with 183,000 miles makes that 30 number. I would suspect that you would need more drop off in PSI for it to be really noticed, unless you are racing Renaults (maybe the only thing a Rover could best in a quarter mile).

Time to change= yes

Are you having any starting or power issues? If not, change the filter and throw a can of 44K in your tank to clean out the engine before it gets cold.

Disco mike- no starting issues, but yes power issues. While driving highway speeds going up an incline steady on accelerater rpm and mph drop steady then truck will down shift and pick up speed. Once back in overdrive it starts to drop again. It will do this all the time. With the occasional sputter and stall when leaving from a dead stop.

How are the wires and plugs. Fuel issues will have a pressure that bounces around?
Are you sure you don't have any air leaks or throttle body clogging issues.

Roving4life- I have already clean throttle body, iac, mass air, plugs and wires were changed not to long ago.the fuel filter was changed when I did the plugs but I just picked up a new one and will install tomorrow and check fuel pressure again. But the truck has been running like this for a while now. And I have about a month to cure this problem as my wife and son will be driving it across country.

Check the fuel pressure at any and all rpm ranges. tape the gauge to the window to see what it is doing. Also make sure the pressure holds for at least ten minutes after turned off. if it drops rapidly you have an issue. Could be fuel pump or injector or something else. If the pressure is good check the compression as well.

update
 

Ok I changed the fuel filter and put new o rings on injectors. Checked fuel pressure and still getting 30 psi. Rev truck to 2000 rpm and held at that rpm. Fuel pressure dropped to 28 psi. Shut truck off fuel pressure went back to 30 psi. After ten minutes of sitting ( not running) fuel pressure went up to 34 psi.

28-30 PSI is below spec, but only by a few PSI. I would be curious what the fuel trims are showing. The pressure goes up after shut off simply due to "heat soak" heating the fuel in the rail up. The good news is, its not dropping so probably not a leaking injector issue, but the pump could still be suspect. I'd like to know what kind of volume the pump is putting out.

I didn't see anywhere, where you stated if the Check engine light was on or if anybody checked for stored fault codes?