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Bugeye fuel pump

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Geary

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I installed a new mechanical fuel pump on my 948 but no fuel is pumping out. My new pump doesn't have the manual priming lever, so I attached a MityVac to the rear carb fuel line and drew a vacuum until I had solid fuel.

At this point I thought the pump was primed but still no fuel pressure. Then I dropped the oil pan and verified the pump lever was sitting correctly on the fuel pump lobe of the camshaft.

What should I check next?
 
Hello Geary,

If the sump is still off, you can do two things; one is to manually operate the pump via it's lever and see if fuel is pumped, this will prove the pump (I know it is new but there could be some foreign matter has got under the valves) and also turn over the engine to see that the cam does actuate the operating lever. Is there a spacer between the pump and the block?, it could be that it is too thick. If the sump is back on, remove the pump and actuate it by hand, and see if it works.

Alec
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With the sump removed I had my son turn the car over briefly and I observed that the pump lever had plenty of travel to pump fuel. Then I removed the pump, manually activated the pump lever and observed working fine pumping out gulps of fuel.

So I reinstalled the pump and sump, then syphoned fuel to the rear carb until the stream was solid. With the hose still disconnected from the rear carb I turned the engine over and still no fuel was pumping out. (There IS petrol in the tank!)

My next suspect is the fuel filter. It installed for correct direction of flow, but there is some air trapped in it. I'm thinking this disrupts the vacuum from the pump.

Next I will bypass the filter, unless you have other thoughts.
 
I think the problem is likely to be the cam lobe isnt contacting the pump lever. Try connecting both inlet/outlet lines to the pump and manually pumping it to see if you can fill the floats. If so, I suspect you have the wrong fuel pump. As an aside, the lack of a manual priming lever is going to be a major pain. The fuel in the pump/lines will evaporate if left to sit for awhile=hard starting. Why didnt you rebuild the original? rebuilt original is often better than new. I dont think bugeye mech pumps used spacers at all. Are you using a 1500 mech pump? -Josh
 
I replaced an original Bugeye fuel pump last year for one of our club members, who actually had an original NOS replacement! He also had a rebuild kit for the original. Even though he sold the Bugeye since then, he still may have the original defective pump, plus the rebuild kit. Send me an email message if your interested and I'll give you his telephone number.
Good Luck, Johnny
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