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#1 Starting the engine with the orig. Lucas fuel pump
Posted: Mon Aug 22, 2022 11:17 am
by Desmo
Hello,
After a long storing period and now the necessary revision of all systems, I would like to try to start the engine again soon. There is fitted a new, original Lucas fuel pump. David was kind enough to give me some first tips on how the submerged Lucas pump works. The pump has been tested before installing and works fine.
Should I consider anything else before the first test or also a maybe hazarding situation? Does the tank have to be full or is the current amount of about 5 liters petrol enough for the first tests?
Thank you for your help.
Best regards
John
#2 Re: Starting the engine with the orig. Lucas fuel pump
Posted: Mon Aug 22, 2022 11:51 am
by Allrand
Hi John, no need to fill but mine wouldn't start with 5L, needed10L.
All the best
#3 Re: Starting the engine with the orig. Lucas fuel pump
Posted: Mon Aug 22, 2022 1:05 pm
by bitsobrits
Due to the fuel pickup in it's deep sump, the 5l should be more than adequate to get a good feed to the carbs. Using some quick math, the entire run of fuel lines and float bowls only takes about .3l to fill (roughly 14' of 5/16 line = .2l plus .07l in the carbs).
When I first started mine up after a fuel tank, fuel filter, and external pump replacement, I test fired it with less than a gallon (~4l) poured in the tank because that's all I had available at the time.
#4 Re: Starting the engine with the orig. Lucas fuel pump
Posted: Mon Aug 22, 2022 3:10 pm
by Desmo
Thank you,
So no "explosion scenarios" etc. It is the first time I am working with such a fuel pump type. Do not like to damage my FHC.
John
#5 Re: Starting the engine with the orig. Lucas fuel pump
Posted: Mon Aug 22, 2022 11:45 pm
by abowie
Desmo wrote: ↑Mon Aug 22, 2022 3:10 pm
Thank you,
So no "explosion scenarios" etc.
John
Shouldn't be.
For some reason I find that if I haven't driven them recently, it takes longer to get my 3.8s to fire than my 4.2.
I wonder if it's because of the different fuel pump. I tend to switch the ignition on and leave it for a minute or two before cranking the engine.
#6 Re: Starting the engine with the orig. Lucas fuel pump
Posted: Tue Aug 23, 2022 7:15 am
by Allrand
Yes you can hear the sound of the pump reduces as the system pressures up, then its ready to go.
#7 Re: Starting the engine with the orig. Lucas fuel pump
Posted: Tue Aug 23, 2022 9:25 am
by abowie
Allrand wrote: ↑Tue Aug 23, 2022 7:15 am
Yes you can hear the sound of the pump reduces as the system pressures up, then its ready to go.
This is not as obvious with the in tank pumps.
#8 Re: Starting the engine with the orig. Lucas fuel pump
Posted: Tue Aug 23, 2022 3:27 pm
by Desmo
Thank you. That means the the Lucas pump do not need to be complete submerged (including the electrical unit) before I can start the first tests?
Best regards
John
#9 Re: Starting the engine with the orig. Lucas fuel pump
Posted: Tue Aug 23, 2022 11:00 pm
by mtnjag
NO, the pickup is way down in the sump that sticks out the bottom of the fuel tank. It will almost pump the tank dry. I have the original pump in my car still going strong although I did replace the pickup strainer sock on the end.
#10 Re: Starting the engine with the orig. Lucas fuel pump
Posted: Thu Sep 22, 2022 7:29 pm
by Desmo
Hello,
Everything is working as it should for a few days. The original pump runs quietly and evenly.
Many thanks for your hints.
Best regards
John