Fuel starving problem

[matt_gsxr]

I like that but, how did you get to the internal screws, Matt?

Reach up through the hole and tighten with a custom (bent at 90deg) spanner. A bit fiddly I'd have to admit.

[adithorp]

Doh! Didn't occur to me you did it before fitting the pump.

I've got draws full of "special" spanners, bent for specific (and rarely repeated) jobs.

[Rad334]

Here's a pic of the blackbird pump in my tank.
I've removed the pump now to see what's been done inside, it seems the pumps just been spun around so the pickups still at the bottom.
The pump just hangs off a rubber hose under the housing you can see in the photo.

[RobMsport]

If this photo is showing a top mounted pump the regardless of the pick-up tube being extended to the bottom , the pump still has to suck fuel whereas underneath it simply gets gravity fed and only needs to pump fuel forward. My fuel injection pump cannot lift ----- are you saying that this pump lifts and pumps like a carb pump
If not then the only reason I can think it works on a full tank , is that the surrounding height/weight of fuel gets it close enough to siphon

[Rad334]

This is the pump as it came out of the tank, the Haynes manual for the bike shows the pump the other way around with the mesh filter inside the dished part. The bike also has a filter after the pump still inside the tank. My filter is outside the tank. So it seems the pump itself is still as it would be in bike but it hasn't got the dish under it to stop fuel starving.

[Rad334]

This photo shows the rubber hose it hangs off. The clamp that holds it is the original filter clamp so doesn't fit the pump properly.

[matt_gsxr]

That is quite a clever bodge. Shame it doesn't work as well as you need it to.
I guess it was done that way because the builder didn't think he/she could seal it properly if it was fitted under the tank.

Regarding these pump sumps. These pump deliver around 1litre/min, and the volume of the sump is pretty tiny, so I am not sure it is adequate on its own to stop fuel starvation. Obviously in the bike it is at the bottom of a fairly narrow tank and due to the tipping of the bike into corners the sump is always at the bottom.

As your fuel pressure regulator is separate you could consider a car one (range-rover perhaps) as they have a swirl pot included I believe.
( http://www.locostbuilders.co.uk/viewthr ... ?tid=77941 for example )

Just a thought.

Matt

[Rad334]

That is quite a clever bodge. Shame it doesn't work as well as you need it to.
I guess it was done that way because the builder didn't think he/she could seal it properly if it was fitted under the tank.

Regarding these pump sumps. These pump deliver around 1litre/min, and the volume of the sump is pretty tiny, so I am not sure it is adequate on its own to stop fuel starvation. Obviously in the bike it is at the bottom of a fairly narrow tank and due to the tipping of the bike into corners the sump is always at the bottom.

As your fuel pressure regulator is separate you could consider a car one (range-rover perhaps) as they have a swirl pot included I believe.
( http://www.locostbuilders.co.uk/viewthr ... ?tid=77941 for example )

Just a thought.

Matt

It is annoying as it works fine when it has plenty of fuel in the tank, had considered just putting all back together again but I'm worried about damaging the pump.
So I think I'll fabricate a small sump to fit the bottom of my tank, make a hole in the tank (smaller than the sump) and lower the pump into the sump.
Sounds simple