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fuel pump

Posted: Sat Sep 08, 2007 8:46 am
by Jay-Minor
my fuel pump is constantly clicking (sounds like it's trying to fill up) and never stops, however there is no fuel going to the carb.
i assume that means it's had it?

Posted: Sat Sep 08, 2007 9:03 am
by ndevans
Have you checked the filter? Also is fuel getting along the pipe from the tank?
Might seem obvious, but is there fuel in the tank? If not the pump will just tick away. You wouldn't be the first to be fooled by a faulty gauge :D

Posted: Sat Sep 08, 2007 9:49 am
by Jay-Minor
ndevans wrote:Have you checked the filter? Also is fuel getting along the pipe from the tank?
Might seem obvious, but is there fuel in the tank? If not the pump will just tick away. You wouldn't be the first to be fooled by a faulty gauge :D
yes there's plenty of fuel in the tank (i put £10 in yesterday)

Posted: Sat Sep 08, 2007 9:54 am
by Orkney
Diaphragm maybe if the pump point arent shot which shouldnt be if they are ticking a lot ?

Posted: Sat Sep 08, 2007 9:59 am
by RogerRust
They are very easy to overhual - Just follow the instructions in Haynes.

There is a filter in the pump that might need cleaning and you can clean and reset the points at the same time.

My suggestion is to take the pump off drain the petrol out then strip it down on Newspaper in the kitchen. This is because there are several plastic spacers that fall out and are easy to loose. Don't worry it is an easy rebuild.

I cleaned and reset mine and it went from

Clic, clic,

To Clic, 2, 3 , 4, 5, 6, Clic. If you see what I mean

The diaphrms and etc are available from the suppliers and much cheaper than a new pump.

Roger

Posted: Sat Sep 08, 2007 10:26 am
by RogerRust
Oh by the way here's a tip.

Hold the metal fuel pipe union gently with a mole wrench when you undo the union nut. Sometimes they stick and the pipe twists when you try to undo it. Its not the end of the world but looks untidy for ever more!

Posted: Sat Sep 08, 2007 11:02 am
by rayofleamington
Another comon cause for this is an air leak into the fuel pipe.
Often this can be at the connector between the fuel pipe and the pump, but it could be anywhere in the fuel pipe (most likely you would have noticed if there was a fuel leak though so less likely to be on the section under the car!)

A very uncommon cause is the petrol tank itself. If the fuel can't get out of the tank, the pump just runs on air/fumes. I''ve only heard of this 2 times in 20 years and both times were after a car had sat for ~20 years off road - therefore very unlikely.

If it is the pump itself then it's worth rebuilding. The old pumps seem to have a longer life than new ones, despite being 30+ years old to start with!

Posted: Sat Sep 08, 2007 11:27 am
by Jay-Minor
i removed the filter and it was ok, put it all back together and now it's all working okay (maybe it was an air lock)?

Posted: Sat Sep 08, 2007 12:19 pm
by RogerRust
There is a non return valve in the pump which, if I remember correctly, is just a brass disc that seals against the backpressure from the carb as the fuel is used up the pressure drops and the pump cycles, but it relies on gravity and the back pressure to seal the valve (there is no spring ) even the tiniest bit of dirt lets the fuel drain back towards the tank. The valve is flushed as the pump operate so is self cleaning. However it is this tiny component that regulates the pump or lets it cycle continuously .
I think that is a fair discription of where the problem lies OR is that how the heart works if you need a new valve?

Posted: Sat Sep 08, 2007 12:33 pm
by alex_holden
RogerRust wrote:There is a non return valve in the pump which, if I remember correctly, is just a brass disc that seals against the backpressure from the carb as the fuel is used up the pressure drops and the pump cycles, but it relies on gravity and the back pressure to seal the valve (there is no spring ) even the tiniest bit of dirt lets the fuel drain back towards the tank.
There's actually two check valves. One opens to allow fuel to be sucked into the diaphragm chamber via the filter and the other opens to allow fuel to be pushed out to the carb. They're both accessed by unscrewing the outlet fitting if you want to check their condition.

Posted: Sat Sep 08, 2007 6:54 pm
by overider
I changed a fuel pump earlier this week and had the same problem pump was constantly pumping but nothing was getting to the filter.
I opened the out let pipe and let a bit of fuel pump into a tin then put the pipe back onto the filter and all was well must have been a air lock :wink:

Posted: Mon Sep 10, 2007 12:52 pm
by Jay-Minor
all sorted now, went for a 220 mile drive sunday without a hitch

fuelpump

Posted: Mon Sep 10, 2007 8:46 pm
by scotb
wot about electronic pump? ebay number 190151197914?

Posted: Mon Sep 10, 2007 8:49 pm
by bmcecosse
Use it at your peril! Standard pumps give years and years of excellent service - and then only ask for their points to be cleaned. It's a no-brainer.

Posted: Wed Sep 12, 2007 8:28 pm
by overider
I have an electronic pump had it on for a couple of year now I did the John O Groats to Lands end in 2006 with on problems if anything it's slightly noisier than the old ones: :lol:

Posted: Wed Sep 12, 2007 9:01 pm
by bmcecosse
I think genuine Burlen ones are ok - but there are chinese copies out there too!