306 Diesel starting issues

have you checked the glow plugs (heater plugs), they can burn out but the glow plug lamp will still illuminate. you dont need to remove them to check they are ok. you will however need to undo the wires connected to them. then simply check for continuity between the terminal where the wire sits and the shaft of the plug. you can also use a test lamp, connect one end to the battery +ve terminal and the other to the plug again where the wire would be connected. if it lights up the plug is fine. you should also check that you have voltage at the plugs while the preheat lamp is on.

as far as the fuel is concerned it shouldnt need bleeding if you havent done anything since the last time it ran, unless you have a leak in the system in which case it should be evident.

If the engine started after using the primer bulb you will have removed any air . If the heater plugs or control relay are suspect you might try switching on the ignition and wait until the pre-heat lamp goes out then repeat this process two more times before attempting to start.. This will show if your problem is electrical or fuel related. Also check for any fuel leaks. Even a slight leak can allow air to enter the system. KF