Lucas pump occasional high rev problem?

[Mitch]

Tis a strange problem to be honest as for the top end revs, i found mine when running lucas used to drop off around the 4k mark as its the gov kicking in and the turbo knocking off but shouldnt be that noticable really on a lucas

Id definitly check filter and pickup in tank as 4waydiablo mentioned then if no luck the following

Definitly a fuel delivery problem id say, could be drawing air into the system somewhere, may be worth putting a clear pipe from filter housing to pump and seeing if any air getting in, usual places can be the actual lid of the fuel filter if not sealed properly, copper washers on feed pipe on pump. is the grenade functional does it go hard when you pump it or stay soft giv it a good squeeze this can usually locate small leaks

Yeah it can be annoying at times, the grenade goes hard, will have to check for any obviously places of where air could be getting drawn in, if it was drawing air surely it would be a constant problem? :/