ot-90 Posted January 30, 2021 Share Posted January 30, 2021 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.. Quote Link to comment Share on other sites More sharing options...
Richard Farrant Posted January 30, 2021 Share Posted January 30, 2021 It is about 23 years since I worked on these, so cannot remember, but an old Volvo truck in the yard where I work has to have the "ignition" switch turned on to bleed through the injectors, try that. Quote Link to comment Share on other sites More sharing options...
ot-90 Posted January 30, 2021 Author Share Posted January 30, 2021 This is vacuum cut off for the pump via electric from ignition Quote Link to comment Share on other sites More sharing options...
cosrec Posted January 30, 2021 Share Posted January 30, 2021 when you mean cant bleed injectors do you mean return to tank (no need) injector pipes it will only spit out when engine is wanging over Quote Link to comment Share on other sites More sharing options...
cosrec Posted January 30, 2021 Share Posted January 30, 2021 Suggest you get sight relevant pages out a workshop manual and follow instruction. RR engine fitted is one of easiest to bleed. Quote Link to comment Share on other sites More sharing options...
ot-90 Posted January 31, 2021 Author Share Posted January 31, 2021 When I mean the injector won't bleed ! And no not the return! Quote Link to comment Share on other sites More sharing options...
radiomike7 Posted January 31, 2021 Share Posted January 31, 2021 How were you expecting to bleed the injector lines by using the lift pump? Quote Link to comment Share on other sites More sharing options...
ot-90 Posted January 31, 2021 Author Share Posted January 31, 2021 I would have thought there would be some bypass through pump using lift pump to injector valve heads? Not injectors.. Quote Link to comment Share on other sites More sharing options...
john1950 Posted January 31, 2021 Share Posted January 31, 2021 A fuel lift/ priming pump only supply's low pressure fuel to the fuel injection pump, to bleed the injectors you will have to loosen the injector pipes one or two at a time and spin the engine using the starter motor. Usually just slacken the injector pipes 1/2 a turn and catch fuel with a rag. Quote Link to comment Share on other sites More sharing options...
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