Join Date: Apr 2019
Location: Bay of Islands New Zealand
Thanked 2 Times in 2 Posts
Rep Power: 1
Re: Fuel lifting pump making noise when first starting engine
Typically a Yanmar has a fuel bypass that sends excess fuel that the engine doesn’t need to run, back to the tank. Well, at least the 4-cyl ones do, no reason to think the smaller ones are different.
So if the engine switch is on and the engine isn’t started, the pump you describe will continue clicking interminably as the fuel cycles back to the tank. These pumps click each time they deliver fuel, yours may click more frequently while the engine runs as a result of the through flow system.
I installed a diesel flow pump normally fitted to a Ford Explorer, pumps adequate volume for a 4JH4E and gently buzzes in the background. The downside is that the fuel is warmed by the through-flow and brings the temperature of the whole fuel tank up. I haven’t had problems yet but I often wonder about condensation, diesel bug and all those other horror stories.