Yes, but it's down to blind faith once the pump is back together. You can observe it moving with the head removed and peering down inside.romie wrote:.. I need to know if the pumps plunger is going back and forth I suppose.
You should find the plunger will go on only one way as it has a pin drive from the cam plate. There is a shim between the plunger and camplate. If this was lost, that would cause it to stop pumping. I'm worried you say it can go two ways....
Also, is the delivery regulator sleeve on the right way round? The rebated edge should face the head. If it's around the wrong way that too might account for it as the plunger will not be able to fill.
Finally, are you sure the delivery sleeve is correctly engaged with the governor lever? It's dead easy to dislodge it when refitting the distributor head.
You should see potent jets shoot out of the delivery valves even when turning the pump over slowly by hand (spanner). I've crudely bench tested them like this in the past...
In fact. that's not a bad idea, set up a funnel feeding test oil into the pump (I use hydraflush or filtered second-hand clean LHM), energise the stop solenoid, spin until test oil exits the return line and by then each delivery valve should "fire" in turn as you rotate the pump.
If all is good, when you rotate it by hand you should feel four very distinct and hard compressions...