fuel pump

[Johny89]

So my york engine with a sims/cav injection pump has started surging at "highway" speeds (85km/h) the speeds sometimes drop but then slowly pick back up.
I already cleaned fuel bowl and replaced the filter.
witch made it better for about 1 tank.
Now it does it again. I think the fuel lift pump might be on the way out but i don't seem to be able to find one (motomobil has a "AC" not for cold start system pump) but i'm not sure it is this one.
Mine has a glowplug on the intake manifold which sprays diesel when used, is this the cold start system?