DafT 244 Posted June 29, 2014 Share Posted June 29, 2014 Hi! I have now bypassed the fuel tank in case there is a blockage stopping fuel getting to the pump.... At least have found fuel pump is ok, it now primes with some resistance on the lever.....however, the fitting on the return pipe (flexy to steel pipe) starts to leak when I'm priming it....Traced flexy pipe up to a 1/8" pipe just under cylinder head...this is fed by a 'T' piece from 2 places, 1, from leak off on the injectors and 2, from the top of the lift pump. Does the fuel cut off solenoid valve (electric) bypass the fuel from the lift pump/injectors and back to the fuel tank? If this is the case, it would explain the starting problem! If it is stuck in its 'stop position' where do I go from here? TIA Gaz.... Quote Link to comment Share on other sites More sharing options...
0 callum daf 45 Posted April 18, 2021 Share Posted April 18, 2021 Thank you for the information Quote Link to comment Share on other sites More sharing options...
0 callum daf 45 Posted April 18, 2021 Share Posted April 18, 2021 8 hours ago, Richard Farrant said: Hi, Forgive me for asking, but you say you cracked the injectors pipes open, but did not mention about bleeding the injection pump. This video might give you some tips, first part the guy is changing the fuel hoses due to "diesel bug" but his bleeding procedure may be useful to you. Thank you for the information Quote Link to comment Share on other sites More sharing options...
0 john1950 Posted April 18, 2021 Share Posted April 18, 2021 When you are bleeding an engine with a mechanical hand priming pump, make sure the cam follower is is off the the cam otherwise you are just moving the trigger and not moving the diaphragm. Crank or hand turn the engine the engine stopping at different stages to check for resistance on the trigger. Those Cummins engines are notoriously difficult to bleed when fitted with a bosh injection pump it seems to need to turn over at speed to get the initial high pressure to the injectors. Remove the stop and throttle linkages off the pump and see if you have any resistance. Some have an electric stop solenoid are there any wires to the pump? These stick and sometimes can be fixed with a little light tap with something small. 1 Quote Link to comment Share on other sites More sharing options...
0 john1950 Posted April 19, 2021 Share Posted April 19, 2021 On some engines to get the system purged of air turn the ignition switch to run then bleed it. 1 Quote Link to comment Share on other sites More sharing options...
0 johnwardle Posted April 19, 2021 Share Posted April 19, 2021 Check the fuel pipe connectors, the pipe is a push fit and over time the O rings perish and air gets sucked into the fuel system. Firstly push the plastic pipe into the brass elbows then try starting it, if it still won't start remove the elbows and replace the O rings. Just pull out the inner ring with a pair of long nosed pliers hook out the old O ring and then drop the inner ring back in. This worked on my Leyland Daf and it started instantly yesterday for the first time in 3 months. 1 Quote Link to comment Share on other sites More sharing options...
0 johnwardle Posted April 19, 2021 Share Posted April 19, 2021 I missed out the important bit 'replace the O ring! 1 Quote Link to comment Share on other sites More sharing options...
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DafT 244
Hi! I have now bypassed the fuel tank in case there is a blockage stopping fuel getting to the pump....
At least have found fuel pump is ok, it now primes with some resistance on the lever.....however, the fitting
on the return pipe (flexy to steel pipe) starts to leak when I'm priming it....Traced flexy pipe up to a 1/8" pipe
just under cylinder head...this is fed by a 'T' piece from 2 places, 1, from leak off on the injectors and
2, from the top of the lift pump.
Does the fuel cut off solenoid valve (electric) bypass the fuel from the lift pump/injectors and back to the fuel tank?
If this is the case, it would explain the starting problem! If it is stuck in its 'stop position' where do I go from here?
TIA Gaz....
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