diesel filter pump

[wildplumdx]

hey my utes starts real ruff ive replaced the fuel lines as they where breaking down cracked etc, went better for a little bit now its got worse, almost like its finding the next weak spot ? maybe.... well my filter yeah how they have that manual pump on top you push down to pump fuel into the filter? yeah when i pump that it goes hard then leave it for 10 seconds and its soft as hell again ? that's shouldn't happen correct ? as that means airs getting in ? its a 4d56

[pajeroboy]

yeah my guess would be air getting in somewhere,had a similar prob with my 4d56,the rear diff breather had been rubbing on the metal fuel line and had worn a tiny hole in it,try putting a bit of clear hose between the fuel pump and the injector pump and also a clear line from the return on the injector pump, i put that one to a second fuel can,hav a look if there any air bubbles going in to pump and coming out,then try doing same thing but just useing the injector pump no filter and the second fuel tank,that way you should be able to determine if it b4 the filter (really easy side to fix) or if it coming from injertor pump (pain in ass to fix).

[Bulletproof]

Does that engine have glow plugs because if it does they may be faulty if it is only missing on startup .
The top of the filter pump will go soft again and that is normal.

To test a glow plug ,take it out and dip its tip in oil and then feed battery power to the terminal and it will instantly smoke.

cheers Richard