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MG MGB Technical - What was I thinking?

Im in my 4th day of MG ownership again (I sold my 1970 midget in '96) after having other cars for a few years. Im actually in a position to be able to run 2 cars, my main car is a eunos roadster (mx5 to anyone else) and Ive had a sucession of cheap & cheerful cars as a 2nd runabout. I then decided to buy an 1971 MGB GT, I did a 200 mile trip in it bringing it home, it ran beautifully so I was well happy and proud of my new toy. Then it played up when starting, (see "battery probs thread") I found a petrol leak, easy to fix next weekend I thought as its not too bad.
But tonight on my way to Sainsburys, it died and wouldnt restart. I couldnt hear the pump ticking (had this on midgets in the past), so I leant out of the car and whacked it, The car started. So I drove off feeling smug, then it did it about a mile on. No amount of hitting or swearing would make it tick again.
I had to ring my dad to come out in his van and tow me home.
In the 8 or so years that Ive been away from the MG scene, what do you do with a pump like this now?
In the past Ive stripped them and cleaned contacts, is this still a way forward?
I seem to remember reading an article about putting the pump inside the boot? is this any good?
I think Ive still got a spare midget pump in my parents garage, perhaps I could fit that.
This is a shame as Ive enjoyed using it this week, and will have to wait for the weekend to look at it.
J M Collins

If you get stuck for a pump contact andy jennings who is on the home page of this site under the adds section he will send one in the post at a real good price i have only owned my 71 gt for a week and already i think i want to marry this bloke
r henderson


J.M.
Having owned approximately 10 MGBGTs [and still running one for every day use ]. I always as a matter of course put the fuel pump in the boot, fitted on the narrow ledge behind the spare wheel. It's a matter of extending the wires to reach and then cut two holes approx 3/4" diameter close to the pump and connect up to the original metal pipes with neoprene rubber hose. The idea of making the holes 3/4" dia. is so that you have enough room to put a rubber grommet in the holes for the hose to go through.The MIdget pump is not the same as the MGB [ actually it's the same as the MINI ], although you could probably hang it on to get you home in an emergency. The rubber bumper MGB's have the pump sticking through into the boot but in a different position to where I normally fit them.You will probably get people saying that putting the pump in the boot presents a fire risk,but the chances of this happening is extremely unlikely. Email me if you think I can help any more.

Harry Walker
H.E.W. Walker

Depends on how old it is/condition. Most advise getting new pump and not have to muck with it again. Haven't heard many over here move pump to boot though guess that is what was done later in series life. Seems like a lot of work for what specific benefit? Guess moisture protection in your clime but initially would try replacing or filing points and see where that gets you, then replace, then move pump as you see fit.
J.T. Bamford

Remember that later cars had a vented fuel tank cap.
Dan Robinson

Suggest bypassing the SU pump and replace with another.
I stuffed a secondhand SUBARU ('82 wagon) pump in that space in the engine compartment above the passenger side guard.
P.N. Sherman

There is no need to go to the trouble of moving the pump.

The answer to your problem depends of cost versus effort. You can strip the current pump, clean up and reset the points, the cheap but recurring option. Alternatively, you can buy one of the replacement SU pumps that come with an electronic trigger in place of the points. These are well sealed and being under the car will not be a problem.

David
David Witham


David

The idea of relocating the pump to the boot is to make it more accessable for any future maintenence etc.I still maintain that the original position makes it very difficult to get at Have you ever had to gain access to the pump on a wet winters night and had to lay down on the wet road to fix it?,this is the sort of scenario when it is far more sensible to have it in the boot!!
H.E.W. Walker

JM - Rebuilding the pump is good IF the swamping resistor inside the coil housing has not been burned out. This happens when the pump fails in a current on condition, usually caused by a blockage on the inlet side of the pump. If the swamping resistor is burned out, the pump will still operate fine, except it will eat points in a very short time. If the swamping resistor is still good, rebuilding the pump should make it as good as a new pump and it should last 50,000 to 100,000 miles (unfortunately, I don't know of any way to determine if the swamping resistor is burned out other than removing the coil from it's housing and inspecting the resistor - I will say that of the pumps I have restored, 90% of tehm have burned resistors). A new Subaru pump, or Honda pump or Fawcet pump should all last 50,000 to 100,000 miles - they are all about the same.

As for changing the location of the pump to inside the boot, I have a different way of dealing with a failed pump o the road. I mounted one of the little square, run all the time, make a lot of noise Fawcet pumps under the car and plumbed it in series with the SU pump and installed a switch to select the pump. If I have a pump failure, I don't even have to slow the car, just flip the switch and continue on home, where I can deal with the pump in the comfort (?) of my own garage. This, however is a matter of personal preferance. Good luck - Dave
David DuBois

Seriously, buy a new pump of one type or another. The cheapest option is a second hand Jap' pump(subaru). Theses SU's are up to 40 years old by now and trying to rebuild (as I found) is an expensive exercise in antique parts that might escalate into major expense. If I recall I paid 50 dollars for a set of points! and then the main coil started to play up.
Peter

I've just had to work on my fuel pump on the B. Not something that was even worth the expense or hassel to do as I saw once I had dismantled it, changed the points cleaned it up, and have it go out in less then a month. (Electrical surge fried it) I've gone and replaced it with a slightly modified import universal inline pump from Masters. It has the same psi rating as the old SU pump, and I was able to mount it almost directly besides the old SU pump housing. With the masters pump I had to go buy a pair of 1/8" threaded plumbing elbows, and a Borsch threaded fuel filter to screw into the elbow at the inlet. While I was down there I also installed an inline fuse to prevent any such surges from wasting another pump ever again.
If anyone likes I can take pictures of how I mounted it for future reference?

Quick tip: If your car had been stored with fuel in the tank for more then two years, drain the fuel completely out of the system, and pour in fresh fuel with a 2 stroke oil mixed in (weed whacker oil/fuel mix) to help flush out the system. Install a clear vue fuel filter in the engine bay (the one with replaceable elements) run the fuel pump until fuel starts to fill the filter and watch for assorted items to flow through. The greenish color of the oil/fuel mix will let you see any debris that might be in the fuel lines, and also help loosen up bits of rust or deposits inside the fuel lines and tank. Then its just a matter of changing the filter element out, pouring in new gas to crank the engine over with.

Have fun CJD
CJD Dark

What caused the surge? An inline fuse is always a good idea as there is more likelyhood of a short at the pump frying the harnesses, but the voltage would have to rise five-fold or more to blow the fuse on a surge.
Paul Hunt

My guess is that the old wiring harness shorted out and trashed the pump. I've gotten the whole wiring harness replaced now, with inline fuses on the most sensitive of peices. The fuse on the fuel pump is a low power fuse type. It's rating is slightly higher then the max power that the fuel pump can take so its a good peice of mind there.
CJD Dark

Not possible. More likely the pump shorted out and trashed the loom.
Paul Hunt

This thread was discussed between 16/03/2004 and 22/03/2004

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