International Lancia Forums

Anyone measured the pressure output of a Fispa etc mechanical fuel pump. I know the spec which is c 3psi but is it fairly constant or fluctuating. I put a mechanical guage on the carb feed and saw steady 3psi from the Facet priming pump but wildly fluctuating from the mechanical when the engine was started (electric pump off). It stabalised at 3psi at around 2-2,500 rpm for a while but then went mad around the 3psi mean.

I plan to remove the electric pump tomorrow and take more readings (and probably buy a red top Facet to use instead).

Tim

I

The original mechanical Fulvia petrol pump delivers at a little over 0.3 bar (4.2 psi). Pressure is constant. If it is not there may be dirt in one of the valves.

Huib

Correct as I replaced the valves with some NOS metal bodied ones (dont no where they came from and are not Fispa but fit). Now I am getting quite constant 4+psi (still fluctates a little at low revs). The old valves had not much miles on them and my fuel is v clean. No dirt in pump at all. And the old flap valves seemed to behave as they should but obviously the change sorted the problem...

Tim