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Fuel pump sporadic

Posted: Fri Nov 30, 2012 8:23 am
by chesney
Morning all,
Yesterday my fuel pump went, as it happens the bakelite cover had chipped and a piece had let the points jam, anyway that pump is beyond repair. So I put one of my 4 spares on it, only the mounting plate (with inlet/outlet) had cracked. So I took this part from the old pump and put it on the 'new'. I then realised the points were past their best, so I replaced them with a new double set I had. I set the armature according to the workshop manual (4 holes) and did chock the rocker with a matchstick to hold the armature while the screws were tightened.
But - the pump now seems sporadic, whereas before you got the perfectly timed click, it pauses and then catches up with itself slightly. There seems no routine to it. While it hasn't given in yet I don't trust it while it is like this. The pump ticks fine when not plumbed in (only tested for a second though) and the valve assembly etcetera came off the old pump.
Is there something I've forgotten to do?

Re: Fuel pump sporadic

Posted: Fri Nov 30, 2012 4:09 pm
by mogbob
The proceedure seems to be as per the book.
Obvious things, matchstick removed but...were there any wooden splinters or for that matter bits of plastic from the chipped cover left in the mechanism ?

Other things...maybe ?
Electrical connections....supply wire sound ? Clean metal around washer / nut at mounting points ?

Pump to Carburetor Float.Rubber fuel hoses not perished / collapsing internally ?

Carburetor...float needle / seating clean no dirt muck..sticking occaisionally ?
Bob

Re: Fuel pump sporadic

Posted: Fri Nov 30, 2012 5:58 pm
by simmitc
Although done by the book, it sounds to me as though you might need to unscrew the diaphragm and rod a turn or two to get the adjustment correct for that pump. Most of these things are approximate to set and then fine adjust as required - assuming that the diaphragm has not gone brittle.

Re: Fuel pump sporadic

Posted: Fri Nov 30, 2012 9:04 pm
by chesney
Got to the bottom of it now. Fuel pump was in fact fine, it was the float bowl leaking. I was so busy looking at the pump I missed the petrol pouring onto the tie plate/manifold :o Odd as it just started with no warning - can't think why? Leaking from the gasket not the overflow. Spare float bowl fired and all good :D Think we will have to call this one a coincidence, can't see how it would be connected. Think I will carry my 2 spare fuel pumps in the boot - just in case.
Thanks for the help everyone, very nearly fitted a fully electronic pump :o :lol:

Re: Fuel pump sporadic

Posted: Sat Dec 01, 2012 7:46 am
by mogbob
Good news problem sorted !
A new fuel bowl gasket a bit cheaper than a new electronic pump too.
You'll have some money left over for the Festive Season.
Bob

Re: Fuel pump sporadic

Posted: Sat Dec 01, 2012 9:13 am
by chesney
Actually the pump was a freebie from a chap who had an MGB, I would bet the psi is too high to use in a Moggie though.
Sticking with electro-mechanical for the foreseeable future (even if it means carrying not one but two spares :lol:).