Fuel Pump Ticking but Not Pumping

[Daniel Kaminsky]

AH BJ8, fuel pump about an 8 yr. old replacement, appears to be from Moss. Worked fine until it stopped clicking. Removed and cleaned points, bench tested with gas and ran it for 30 minutes perfectly. Put back on car, disconnected fuel line by carbs to lower resistance, ticks continuously but will not pick up fuel. Took off fuel line filler cap, tried again. No luck. Suggestions?

 

[BobHaskell]

Outlet pipe is at the top of the pump, right? Could try pressurizing the fuel tank by blowing into the tank, sealing your mouth to the fill tube with your hand.

 

[red57]

Could be the fittings in the line from tank to pump are not sealing well causing a vacuum leak allowing air to be drawn in instead of fuel. It's possible to have a vacuum leak without leaking fuel at these fittings.

 

[Daniel Kaminsky]

It has been mentioned to put pressure in the tank. I was thinking of renting a small compressor, but maybe mouth pressure is enough? Also, the fitting is odd to me. The in/out lines attach just where the two large bolts pass through to secure them into the pump. It seems to me that they (the bolts) would block the flow of gas? Do all BJ8s have this setup? But I replaced it just as it was before, when the pump worked. Confusing. The upper line might not be seated just right. Will check it.

 

[Bob_Spidell]

Likely inlet line air leak, like Red suggested. Be gentle, the pump bodies are soft ('pot?') metal and it's possible to cross-thread or strip them with the steel bolts. Did you mess with the diaphragm/body side of pump at all? Did you use new fiber washers (some pumps have O-rings)?

The fittings are called 'banjos,' for their shape; also found on carbs and oil feed line for the valve rocker. The bolts ('banjo bolts') are hollowed-out, and have a hole (or two?) through which fuel/oil passes. AFAIK, all 6-cyl cars used hard copper lines with banjos fitted; 4-cyl pumps used compression-type fittings with hard lines. Owners sometimes cut the hard lines and install flex lines to fit aftermarket pumps.

 

[Michael Oritt]

Or it could be a clogged fuel line anywhere between the tank pickup and the fitting to the pump.

 

[BobHaskell]

Likely inlet line air leak, like Red suggested. Be gentle, the pump bodies are soft ('pot?') metal and it's possible to cross-thread or strip them with the steel bolts. Did you mess with the diaphragm/body side of pump at all? Did you use new fiber washers (some pumps have O-rings)?

The fittings are called 'banjos,' for their shape; also found on carbs and oil feed line for the valve rocker. The bolts ('banjo bolts') are hollowed-out, and have a hole (or two?) through which fuel/oil passes. AFAIK, all 6-cyl cars used hard copper lines with banjos fitted; 4-cyl pumps used compression-type fittings with hard lines. Owners sometimes cut the hard lines and install flex lines to fit aftermarket pumps.

Bob,
Fuel lines are steel. Unions, some with right angle adapters, were used until the fuel pump (AUA 173 LCS) was moved to the right hand side of the car during 3000 MkII (BT7/BN7) production. Banjo fittings were then used to the end of BJ8 production.

If you have the Concours guidelines, there's a supplement written by Roger Moment covering the Big Healey pumps and change points. Originally published in Austin-Healey magazine (date not given in the guidelines).

 

[Bob_Spidell]

"Fuel lines are steel."

Yep (I seem to be on a tear for giving incorrect info). Are the banjos copper or similar plated?

 

[BobHaskell]

Bob, the banjo bolts are steel and have two side holes. The banjos are non-magnetic. I would guess that they're brass, but don't know.