Postby Hasbeen » 12 Aug 2015 07:16
sgstepp your pump is obviously pumping a little, but not producing enough pressure. The pump is very simple, & only a few things can cause problems.
Firstly was it working when the car was parked? Has this occurred after some period of sitting with no use, or has it developed over time? Slow failure points towards a diaphragm problem.
Your pump has a diaphragm which does the sucking & pumping. This is lifted by an arm driven by the jack shaft, opening up the pump chamber, & this compresses a spring. The spring pushes the diaphragm back down, reducing the chamber & pumping the fuel.
The flow is controlled by 2 valves. The inlet is opened by the vacuum as the chamber is opened, allowing fuel to flow from the tank. The vacuum also closes outlet valve, preventing flow from the carbs. When the spring closes the diaphragm, pressurising the pump chamber, the inlet valve is closed by the pressure, preventing back flow, & the pressure opens the outlet, pumping fuel to the carbs.
The problems can be;
1/ restricted or blocked fuel line or filter reducing or preventing flow.
1 A/ clogged strainer in the top of the pump, or in the tank.
2/ dirt or wear causing either of the valves to not close sufficiently.
3/ split or holed diaphragm.
4/ Broken or week spring.
5/ broken worn or bent pump arm.
6/ leaking hoses.
I'd check for dirty/clogged filter, hoses or strainer first. Then the pump diaphragm or valves. These are not available as TR parts, but in Oz 50/60s Ford Major diesel tractor kits, [about $15] fit.
To increase the pump output you only have to reduce the thickness of any spacer/gasket by 50 thou, [1/20 inch] to make a big difference. Our carbs don't like much above 2 PSI fuel pressure.
Don't be frightened of the pump, they are not rocket science.
Oh, & good luck.
Hasbeen