Hi Jarek
I had the same issue. The electric fuel pump clicked away, but there
wasn't enough pressure to push fuel up to the carburettors. I dismantled
the pump and found the electrical contacts badly worn, and not worth
trying to repair. Also, the pump has a life of only 1500 hours, so I
decided to replace it. Fortunately I could purchase a replacement Hardi
pump directly from the manufacturer in Germany with no hassle. Now the
pump pressure is great and plenty of fuel gets to the carbs.
Incidentally, I also found that although the fuel hoses had been
replaced as scheduled the intake screen at the fuel pump had not been
cleaned, and had what looked like glass fibres in it - despite my Dimona
having been changed to an aluminium fuel tank.
The electric fuel pump is not per your diagram. There is a later mod to
the fuel system. The electric pump is installed underneath and just
forward of the fuel tank - very awkward to get at - and is plumbed in
between the tank and the shut-off valve. This means there are two fuel
pumps in series - electric first, then the shut-off valve, then the
engine-driven pump. As long as one or both pumps are operating fuel
will get to the engine.
Hope this helps.
Kind regards
Martyn
On 12/11/19 12:01 AM, Jarek Steliga wrote:
Hi,
How to make sure the pump functions properly? Does it produce some
audible buzz sound when switched on? When I disconnected the fuel hose
at the carburetor and switched the pump on, no fuel flowed.
Is this pump just a back up in case the main engine driven pump fails
during take off / landing?
What is the electrical pump's location relative to the shut off valve?
As per diagram between the fuel shut off valve and the carb?
Tank you in anticipation
Regards
Jarek
