G'day Sean165.
Remove the fuel RETURN Line from the front of the Injector pump and get an old Speedometer inner cable cut the square drive of the end and you have a good flexible pipe cleaning rod, or use a piece of wire and run it all the way through to prove the pipe is clear.
Look inside the fitting where the pipe goes into the pump and you will see a rubber OLIVE sealing ring, Quite often they go hard and either block the hole or allow air to enter the system
These are the ones that cause the problems when the pipe wont come out of the fitting,Check and replace ALL OF THEM and make sure you get the correct size for the pipe, If you try to fit the thick ones you will strip the threads on the aluminium housings.
The fuel lift pump:
It has a rubber diaphragm which is known to fail and leak this can also cause air in the fuel system, You mentioned that the lift pump has no pressure behind the lever ,there should be at least Spring pressure as there is a return spring in there ,if you cannot feel Spring Pressure remove the pump and fit a new lift pump it is just as cheap as a kit and less hassle, make sure you use good quality gasket sealer and spring washers on the pump mounting bolts/studs and be carefull when refitting the pipes as it is very easy to cross thread them.
Priming the fuel system :
With the engine stop out and the priming lever held down with light pressure Crank the engine and you will feel the lever going up and down this is the pump follower running on the camshaft so you want to crank the engine a little bit at a time and stop when the priming lever is at the upmost position,that is at maximum operating stroke this will allow you to hand pump maximum stroke.
As you have done loosen the bleed bolt on top of the secondary filter the one with the thin return line on and operate the priming pump till you get a good flow keep pumping for about two minutes and look for air building up in the system ,if all is good go next to the injector pump Bleed screw on the bottom of the pump use a 5/16" A/F ring spanner ,loosen one turn and again prime for about one minute you should get a flow that shoots out about one foot and more ,when satisfied all air is out do the one near the top of the pump same way ,go from there to ANY Injector pipe ON THE PUMP 5/8" a/f Spanner There is no need to go to the injector, Pick the easiest pipe nut to get to and undo one turn set the throttle say half way ,stop in and crank till it starts, in the interests of safety stop the engine and tighten the injector pipe.
Fuel filters:
If you have not changed the fuel filters this would be a good time to do so making sure you change ALL THREE O RINGS on each filter they should be supplied with the new filters
I recomend you use CAV Filters Part number 296.
Also another place to check for air leaks is the small through bolts that holds the filters on there is a small copper/aluminium sealing washer under the head of the bolt,replace them both.
hope this helps.
regards.
Hutch.
