Electric fuel pump

1971 mgbgt- can someone recommend the correct replacement and source that has worked well for you. I've heard time and again the OE pump is nothing but an accident waiting to happen.

I haven't had any problems with the OE pump. The only time it didn't work is when I tried to start the car after it had been sitting for years. Hit the pump a couple of times with a wrench and it started working. The pump is 31 years old.
A universal, low pressure pump can be used in its place and generally cost less.

Lots of people will say to stick with the SU and that it is very reliable. Other people will say that you could buy a solid state SU and do away with the points. I can't disagree with either statement. My word of caution is that if you do get rid of the original pump and install a aftermarket pump it may be hard to find one that has low enough psi rating, and will require a psi regulator. I am not sure but I think that the carbs only need 3 or 4 pounds. I am sure someone will know. I replaced my pump with a aftermarket only because my old one went out and I needed the car so I got one at Auto Zone and had to get a regulator for it.

Lots of people will say to stick with the SU and that it is very reliable. Other people will say that you could buy a solid state SU and do away with the points. I can't disagree with either statement. My word of caution is that if you do get rid of the original pump and install a aftermarket pump it may be hard to find one that has low enough psi rating, and will require a psi regulator. I am not sure but I think that the carbs only need 3 or 4 pounds. I am sure someone will know. I replaced my pump with a aftermarket only because my old one went out and I needed the car so I got one at Auto Zone and had to get a regulator for it. One more thing to remember is if you unhook your taillights the pump will not work. It gets is ground from the same place as the lights. I found this out when I was painting a MGB once and spent two hrs. trying to get the car to run to move it.

Steve, you've been hearing wrong. From what I can tell, the pump in my '73 is the original, and 35 years later it's still merrily ticking away.

PS - yamahauler Wrote:

I love my SU. It's the original pump, and works great. I did have to replace the points shortly after I bought the car, but it was a fun learning experience, and it's worked perfectly ever since.
-Dominic

Ditto with Dominic

I've no problem with either SU (points or electronic) or aftermarket "cube" pumps. They all do the job, and the SU is not "an accident waiting to happen."

The SU carbs need around 2 psi. I've never had trouble finding one.

The pump from an 82 subaru works very well.
I just happened to have it one day when the SU failed me (again) and I was in a hurry.
I wrapped some foam mat around it for noise insulation and pushed it into that corner at the side and top of the engine compartment, out of sight. There is a sort of compartment in there. Port side on my car, because the master cylinders obstruct on the other side. For you it works out even better, you can put it on the starboard side, right above where the fuel pump wire/power (running to the back of the car) plugs in. A better spot than down in all the dirt under the car. Easier to get at as well!. The Fuel lines (filter before the pump) and location kept it securely in place. Took about 15 minutes to do. I went to the trouble of removing the SU(another half hour) however It turns out that I need not have done this. You can pull fuel through the SU valves no problem I'm assured.
This worked great, no pressure issues, it even sounded the same, until I put the fuel injected V8 into the car. You need a high pressure pump for these.
Apparently Honda civic pumps also work well. My Subaru pump has a Mitsubishi symbol on it, so a Mitsubishi pump might do. Any carby' pump is my guess.
If you are getting the pump off a wreck, it is located at the rear top port side of the engine compartment, and is very easy to get at and remove.

I've had some "original equipment" pumps that work and some that don't.
That experience, coupled with the variation in opinions about the pumps makes me think there was a quality control issue lurking about.
They always find the most inopportune time to quit, and striking them sometimes will get the points to work again. When I had an OE pump in the car, I always carried a spare pump in the trunk. Once I installed a square style with a pressure regulator. Hasn't failed (or needed me to hit it with someting) in 25 years. Now I only keep a distributor cap, wires, tools and fuses in the trunk. (No spare no lug wrench.)

i bought an original replacement , points type, from VB for 99 $ ,i love it.

i kept hearing reference to the chartieristic 'ticking' and wondered what the deal was. the old one i had was so weak i never heard a tick from it ...

the Brand new SU original replacement part , point type, is what i say go with, the darned things are bullet proof and will run the car even when thay are way gone into failure...

You can buy 3 replacement facet pumps for the cost of an OE. That's what I run, and I keep a spare handy as it will work in any of my cars.

check these articles in the library


http://www.mgexperience.net/article/backup-fuel-pump.html

http://www.mgexperience.net/article/su-fuel-pumps-101.html

When I bought my 74B it had an aftermarket pump in the engine bay. The original SU was still hooked up. Since then, that aftermarket gave up the ghost and I replaced it with yet another aftermarket.

I thought I would go back to originality so I bought a new SU electronic pump. I took the aftermarket one out and went to remove the original SU pump. When I was doing that I thought "what the heck!". Gave it a whack with the wrench and tried starting the car. Started right up. That was last year. No problems since.

Now, I've got a spare aftermarket pump, a new electronic SU and a 35 year old "accident waiting to happen" that works like a charm.

SU fuel pumps do not have mechanical problems, they have mechanic problems.

A properly rebuilt SU fuel pump will last as long as any other pump (and has the virtue of being rebuildable).

If you are really nervous, get Dave Dubois to rebuild it for you and convert it to electronic switching.

Guys, if I may weigh in with my opinion on SU Pumps. They're really quite reliable and from a theoretical point of view, the points in an SU Fuel Pump function very much like a set of ignition points. You have a set of points which are normally closed and they are connected to a Coil with a capacitor across them to reduce arcing. Putting 12 volts to them causes the Coil to pull on the diaphragm and draw fuel into a small chamber and also break the electrical contact in the points. Breaking the contact allows the Diaphragm to "relax" back to its original position forcing the fuel to the Carbs and remakes the electrical connection starting the whole cycle over again. The main wear item is the Points just like in an ignition. Because they cycle at a far slower rate than the ignition points, they last much longer. In my humble opinion, they should last about 75 to 80,000 miles.
I once had the OE Fuel Pump quit on a long trip. Jacked the car up, removed the pump, opened it up and removed the center contact point. I was along side a concrete sidewalk so I rubbed the points on the rough concrete surface to clean them up. Reassembled the pump, turned the key and that wonderful clunking sound was heard. Can't get much simpler than that. They lasted several thousand miles before I got around to replacing them. And when you replace the points, leave the mount in place, spreading it apart until the points can be removed. That way you don't have to adjust the solenoid/diaphragm mechanical connection .
Sorry if this sounds like a lecture. I've seen many pumps replaced when the real problem was worn corroded points. Kind of like replacing the distributor when the ign. points are bad.
John Valentine

I don't like SU fuel pumps much, they've given me some serious grief.
You do need to replace the points every so often. I was charged ALLOT for these points, $60, perhaps I was ripped off. You need to adjust the Diaphragm (winding it in and out) so they kick over with the right pressure. This is all very time consuming and involves crawling around under the car getting covered in petrol. Also the points will form an oxide coating if the pump isn't run regularly. In my case there was also some sort of weird fault with the winding in the armature, the main body of the pump, which meant that the thing would often not work on large metal bridges in the rain. Keep in mind these pumps are usually about 40 years old and a design that is about 80 years old. They are going to be fairly worn. How ever a brand new SU pump should work very well for a long time, oxide issue aside.
I don't know if the SU will push through a subaru pump (it probably will) however it would be very nice to have that backup pump tucked away ready to go.

Peter - "I don't know if the SU will push through a subaru pump (it probably will) however it would be very nice to have that backup pump tucked away ready to go." You stated earlier that the pump in the Subarus are Mitsubishi pump, so the answer is a definite yes. The Mitsubishi is a clone of the SU fuel pump and just uses check valves inside. The best place to have that backup pump (an all electronic pump so there are no points to film over), is installed in line and wired through a switch so it can be brought into play with just the flip of that switch. That way, you don't have to get under the car until you are safe in the garage at home where you don't have to worry about some inattentive driver running into your car at the side of the road while you are under it (see my article at: http://www.mgexperience.net/article/backup-fuel-pump.html).
Cheers,