Reason of SU fuel pump strike

[germanmichel]

Hello at all from sun shining germany,.. you know I`m not live in california....;-)
But nevertheless I have some question to the SU fuel pump on my 61, BT7 with the orginal pump.
The pump will work fine,but after longer staying the car (more than 30 days) the pump will not work. The contacts are clean and not outburned and they are adjusted.
After knocking on the pump the pump is still working. Does anyone know what is the reason of the "hanging" ?

Bye michel-who was at the weekend on the Historic grand prix racing nürburgring (Top!!!)

 

[Ed_K]

Just a shot in the dark,
If the points are clean but yet a hammer hit to the floor will make it work for another month, you must have a poor electrical connection to the fuel pump including the ground. Look inside the pump as well for signs of a poor connection or a thin wire right at an electrical connection. Take apart and clean all of the electrical connections in and to the fuel pump. Just doing that may fix the problem.
One other thing, examine the wire that supplies power to the fuel pump especially in the area where it turns from running down from the engine compartment to going back toward the rear of the car. In this area you may have some wire insulation missing. A hammer hit may move it just enough to work for a while. I was missing a foot or more of insulation in this area but my fuel pump was still functioning.
Ed

 

[germanmichel]

Hello Ed,
thank you for your information. I will check the electrical connections. I know that the ground come only over the support not over a wire connection..so I think you on right way with your ideas.

Thank you.

michel-who has only experience with triumph cars

 

[GregW]

...I know that the ground come only over the support not over a wire connection...

Hmmmm, I have a '67 BJ8, so things may be different. I do have a seperate ground wire. See the blue arrow in the photo.

 

[Stretch]

I had a new set of points that had a slight interference when the mechanism flopped over. Sometimes it would hit just enough to hang up. It was hard to see. All that was needed was a slight mechanical adjustment.

 

[germanmichel]

Hello @ all,

I did not have a chance to check your very good advices. My second hobby is my job....
But if I found the reason I will give here a feedback.


yours michel-who thank you for "overnight support" :banana:

 

[Richard3000]

Hi Michael,(greetings from Switzerland)

I also have 61 BT7, which I rebuilt about 10 years ago. Having messed about with new points, in the end I bought a new SU pump. Now it is starting to play up again if it gets very hot. I think these pumps are intrinsically a bit dodgy and not helped by being positioned right over the hot exhaust. If I were doing it again I would definitely re-position the pump somewhere else (in the boot?) and to be honest I would probably go with a constant flow aftermarket pump. There are many out there.

hope this helps,
Richard

 

[tahoe healey]

get a cheap replacement and use it until you get the bad on fixed. Then carry the cheapy in the boot for emergencies. The guy that rebuilt mine made it look and act like new. As he said, not much cannot be fix as new. And my old one is 45 years old and worked fine but leaked. It is waiting to be put back in service in 45 more years cause I bought a new one I'm now using.

 

[GregW]

If I were doing it again I would definitely re-position the pump somewhere else (in the boot?)

Hi Richard,
The later cars moved the fuel pump to the other side of the car on the heel board. My photo earlier in this thread shows the location.

 

[AUSMHLY]

Maybe replacing the fuel pump with a modern design may help. Here's what Moss says about theirs:

New from SU! Electric fuel pumps with modern, reliable, electronic, solid state switching and control which eliminates the use of contact breaker points. Now you can have a vintage looking SU fuel pump with peace of mind that only an electronic fuel pump can offer. Plus the characteristic ticking is retained.