It has been a long time since the fuel pump had been rebuilt, converting it from mechanical to electronic actuation in the process. Burlen Fuels offer an electronic conversion kit to overcome the known issues with point corrosion with the mechanical set up. While it would have been cheaper to buy a new pump, by reconditioning/converting it, I would gain a much better understanding of how it worked which might prove useful if there are issues in the future.
The electronic set-up had already been tuned to its maximum pumping speed, by rotating a Hall Effect fork. I just needed to check the flow rate was close to the designed 2.4 pints per minute by bench testing it with some paraffin before putting it on the car.
The pump raced when it wasn’t under load. So far, so good! However when the inlet pipe was placed in the bucket of paraffin it didn’t quite go as planned. It stopped immediately! I tried retuning the electric circuitry by repositioning the Hall Effect fork through its full arc of travel but it still refused to pump. It was a bit gutting having spent all that time and effort.
The technical department at Burlen Fuels thought it might be due to reverse pressure which would naturally slow the pump down. Although I wasn’t convinced as the outlet was simply pumping back into the supply bucket. I was running out of options and was starting to regret not buying a new pump!
I refitted the magnet attached to the end of the diaphragm spindle in the hope that this might be limiting its travel and therefore the strength of the pump. Eureka – the pump continued under load but at a much reduced rate, which would be expected.
The proof would be in the achieved flow rate which, over three tests, averaged out at 1.6 litres or 2.8 pints. Phew!
I was now happy that the pump was in working order and could be refitted to the car.