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MG MGF Technical - Fuel Pump Problems - Help!!

Yesterday my fuel pump seems to have decided to stop pumping. Probably my fault it stopped. Any thoughts or suggestions there?

What I have observed did.

I was replacing the battery cables and adding a ground side cutoff switch on my car. During the same install / electrical work I was adding both a voltage meter and a vacuum gauge.
When I pulled the battery, the ground wire that goes to the fuel pump was caught on the battery base and broke. I could not see where the ground cable went from the top of the battery compartment.
I could only see a spade connector and a silver or chrome piece what I thought was the end of a bullet connector.
Without doing anymore investigation, I pulled that connector out (not easy) and soldered the ground wire to it. With an ohm meter, it did show it was grounded. I then hooked up the wires and reinserted the battery / battery cables.
The new cables and the cutoff switch worked perfectly. The car fired up and ran.
When I turned the key, the voltage meter did not register. I had tapped into the same line as the voltage for my radio which also did not work.
I ran the car several times and for several minutes trying to trouble shoot the problem and it shut down lack of fuel.
I then decided to tap into the white wires under the dash for the volt meter source. Thus without knowing it, I compounded my potential problem solving.
There were three white wires coming into a double bullet connector from the dash side and one white wire coming from the switch bundle I believe. Since I wanted to add one more wire I pulled the double connector and replaced it with a triple connector. I made up a white wire with bullet connector for the voltage meter. I then inserted all the wires into the tripe connector. When I turned the key, the volt meter read correctly but I did not hear the fuel pump click. Radio worked fine but it appeared I had no power to the fuel pump.
I pulled the battery as I could not get the fuel pump connectors with it installed so I could do a resistance check on the wires. I was not getting a check to the positive side of the connection. I took the volt meter out of the system and replaced the triple with the double connector just to set things up as original. Still no luck.
Next I went to the fuse box to see if I was getting power there. Here some weird things popped out that I did not expect. I pulled each of the white wires at the fuse box and expected one to be the right wire for the fuel pump. None checked out but when all were disconnected and I hit the connecting spade bundle, I did get a good resistance check which makes no sense to me. I took out the fuse (original Lucas fuse that said 35 amps on one side and 17 amps continuous on the other side) and got the same and then realized it was probably coming from the brown wire above.
I then got under the car and saw that I may have hooked up the ground wire to the wrong connector as there was another wire down there that went to a spade connector and an added ground. This wire had a crimp splice in it which appears to be where the wire broke at. So I removed the wrong ground I had created and put the wires back together.
Everything looked fine so I again reinstalled the battery and cables.
I turned the switch and heard the fuel pump click.
I then tried to start the engine.
Still no fuel and the pump stop clicking
At that point I was fried and stopped to reread the info I had on fuel pumps. I think I have an original pump given its condition but it is hard for me to tell. The positive lead points into the battery box area and the negative or ground spade is pointed to the ground at the bottom of the pump. (I can send photos if that would help.)
The connector I took off may have been some sort of adjusting screw and it is toast at this point as far as being functional. I cleaned the solder out of it and reinserted it in the black elbow it was in but it does not want to stay in place.

Im tempted to directly run power to the pump from the battery to see if I have a switch or some other wiring problem or if the pump is dead. Rumor has it to hit it with a hammer to get it going but that concerns me but will do if you recommend. I can or will run a new white wire to the fuse box if you recommend that.

I really want to get this fixed today so I can drive the car to Buttonwillow and run it on the track this weekend. Moss sponsored event.
Any direction or thoughts would be most appreciated..

Steve Vandal

Steven O. Vandal

Mistake correction:

What I orginally soldered the ground wire to was the breather pipe, not an adjusting screw.
Steven O. Vandal

Disregard all - posted this on the wrong site Should have been MGB Technical. Sorry.
Steven O. Vandal

Completely fascinating though Steve. Good luck with it.

Ed Clarke

thanks for the load of memories Your posting revealed ! Many years back when I was doing Mini-rallying in the deep forests of Sweden 2 SU pumps was a minimum to reach the end of each stage ... Saw in one of the mags that there is a nice solid state switching avaible for those pumps now.

Regards , Carl.

This thread was discussed between 02/05/2002 and 03/05/2002

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