Hi all, been having problem with my drops injector pump, firstly it had a leak from original lift pump (spring return type) which let in air and engine cut out after 15 min or so, changed for the older type unscrew top and pump it up and down one which seems ok, but the vehicle due to covid 19 etc has sat around for a year and done very little.. and now I can't bleed injectors when pumping lift pump as it seems the bosch injector pump housing is pressurising and when priming using lift pump, using finger to block bleed bolt on top left of pump housing pressure is released when I remove finger..This does not seem normal, would the valves inside the injector heads be stuck and causing this or something in the pump that has seized or stuck, have fuel coming in to fuel filter and into pump housing etc but it seems like when lift pumping nothing is going into the top of the injector pump high pressure side.. can only get fuel bleed to injectors when cranking and using wd40 etc..