AP Fuel pump

[flyinghorse1]

Peter,
I once had a brand new AC pump and found that the diaphragm was cut at one of the screw holes. (the small screws that go round the outside -about 6 of them.(Lotus elan)

I have also built the Bristol 400 pump I have on my car and the diaphragm rod is hard to relocate in the actuiating lever (like geoff describes).

You say one key thing for me--the manual primer works,suggesting poor mechanical engagement somewhere---note the pump when fitted rides on top of the camshaft. On the lotus you could put it on underneath if you were not careful and get no pressure--I recall this when fittinmg to my 400 as well. I would turn the engine over on the start handle so the cam lobe is at a low point.

I am assuming your diaphragm rubber is nice and shiny and not destroyed to just cloth by methanol in the fuel.

I also test the pump on the bench before fitting to ensure flow direction is ok & all works.

If you are fitting a electric pump a lot of people use Facet red or silvertops with a filter king filter & pressure regulator.
(made by Purolator Products Company, Elmira, New York. The UK agent/distributor can be contacted on 01784 493555 )
I would fit it out of sight at the rear of the car underneath.

Be careful with polarity of your car & the pump (ie positive or negative earth) and you will need to make a small blank plate for the mechanical pump or just disable it and allow the electric pump to push fuel through it for a period look.

Graham

[Geoff Dowdle]

Peter & Graham ,
further comments
1. you need one paper filter between the pump & the rear carb ,not two on the suction side , this could be a part of the problem with the pump having to suck through two filters that could be partially blocked.
2. An Electric pump at the rear will push the fuel through the original AC pump , my AC Ace Bristol was set up like that .
2. I agree Graham a pressure regulator might be needed at 4.5 psi or the needle & seat could flood the carbs .
More Problems ,Polarity another problem .

3.I'd buy a low pressure SU pump as a temporary fix (even a used one )which will give 2 - 3psi for the wedding then fix the AC Pump , as I have mentioned before they are a very simple forgiving design .
Geoff

[peterg]

I am loath to put a filter between the pump and carb as it is the original solid copper pipe.

The casting number on the lever is 822N3 (or the N could be 8).

Incidentally both filters are new. Location of the cam is an interesting issue that I haven't considered before. The polarity isn't an issue as it has been rewired negative earth.

[Geoff Dowdle]

Peter,
you might have the wrong pump lever fitted.
The two original pumps I have are fitted with levers of casting number "1524280"

The Standard Vanguard pump I have uses 1524043 which is quite different .

I've attached a photo of the pump lever and sketch which shows the angle between the working surface on the cam and the machined surface between the locating tit of the spring and the pivot point hole of the lever is approx. 60 degrees .

http://www.bristolcars.info/forums/a...1&d=1397080785

If you have the wrong lever I doubt that it will work except at idle .

Geoff

[flyinghorse1]

This is the fuel pump from the Bristol manual (400) its a UG as previously indicated. I assume you have both springs.

[flyinghorse1]

Peter-Did you all get to the church on time?

Graham