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MG MGB Technical - Dead Fuel Pump

My brand new SU electronic fuel pump appears to have died. The pump worked fine after installation in March, but I let it sit for a while to prepare another car for several trips including MG 2006 and now it does not work. Any thoughts on what to check with out tearing into and voiding any waranty available? I have checked all connections, confirmed power with a voltmeter and now removed and hooked up directly to power, still nothing.
Scott Shirk

Have you tried tapping it with a screwdriver handle?
Kimberly

Hi Scott.

This is not unusual after standing, and Kimberly's suggestion of giving it a tap stands a good chance of getting things moving. Tap the body of the pump near the plastic cap, but not the actual plastic cap.

If that doesn't work make sure that you have volts on the input connection and NO volts on the body (suggesting a bad earth).

If still no joy, remove the plastic cap and carefully and gently clean the contacts with a little rough paper (yes, heavy ordinary paper), don't get the 20 grit emery cloth out !.

Don
Don

If I'm reading Scott's post correctly he has the full electronic fuel pump without contacts. No hammer needed or cantacts to clean. Dave DuBois may have some tips for additional checks on this type of pump.

Clifton
Clifton Gordon

Hi all.

Guilty as charged, I answered a question that I thought I knew the answer to, not the question that had actually been asked !.

My suggestions regarding checking for supply volts and a good earth now seem more relevant.

Don
Don

I like Don's second suggestion much better. The all electronig pumps, having no points in them, don't respond to tapping.

Scott - you might try connecting the pump directly to the battery (positive to the power terminal and negative to the pump body or ground lug) and see if it runs. If it does, then you have a power or ground problem as Don suggests. If the pump doesn't work when connected directly to the battery, then the first thing that I would suggest is to contact the supplier and and see if you can get a replacement pump, the original one obviously being defective. if all else fails, contact me at the above e-mail address andI'll see if I can walk yu through getting the pump going again. I have an article on fuel delivery troubleshooting at: http://www.custompistols.com/cars/dave/ddFuelDeliveryTroubleshooting.htm
Just use theortion of the article that deals with power and ground problems. Good luck - Dave
David DuBois

David, I have removed it and connected directly to a battery, you can feel a faint hum/vibiration but no action. It acts like it is stuck. The pump probably has not run more than 10 minutes. I will ship it back to the supplier (VB) tomorrow. This is the first electronic pump I have bought, installed the points type on the other cars, one approaching 30 years old on my 58 A. Are the electronic pumps proving depenable or should I stick with the old style?
Thanks everyone
Scott Shirk

Afer two dissapointing failures with expensive SU pumps I went cheap. I was a little sad to do so as I like keeping things original when possible, but felt compelled to do so in the end when I almost got stranded out in the country past midnight after I was returning home from an evening wedding using wedding cars sevenoaks(not mine, a passing friend who also attended the same wedding picked me up and returned with me to change out the pump for the final time.) The other time was in the snow at 4000ft. Tapping the pump worked then, I don't know how old that pump was but it was soon replaced. Here was my solution.

http://www.mgaguru.com/mgtech/fuel/fp201.htm

-Jared
Jared Snider

I ran a fuel pump from an early 80's subaru that happened to be in the driveway. Apparently a Honda civic one will also work well. Check the archives.
I bypassed the SU (left it there as a decoration!)with a bit of fuel line and put the Subaru pump up in the engine compartment.I didn't even have to bolt it in. Just wrapped a bit of foam rubber around it and stashed it in that odd little space in the extreme top corner of the engine comparment out of sight. It was a temporary fix that worked so well, I left it there until I installed the V8. Took about half an hour to do.
It even sounds the same as an SU. I plumbed the filter before the pump.
The power for the fuel pump runs back from a bullet conection near the fuse box, which is easy to hijack.
Peter

Scott - The all electronic pumps had some problems in the early years, but that all seems to have been ironed out now. I have a pump that I installed the all electronic modification in our MGB now and it has run without a hicup for about 5 years now. I did find out one thing when I visited Burlen Fuel Systems a couple of years ago when we were in England. It seems that if a clog on the inlet side of the pump causes the pump to fail in a current on condition, the internal swamping resistor in the coil burns out (this is a common happening with the later SU fuel pumps). Once the resistor burns out, the all electronic pump will no longer function. This may be the situation you are dealing with. If you have an old fuel tank, the internal filter screen could be clogged up, causing the pump to stall. Or, if you have an external filter between the tank and the pump tha has gotten clogged, the same thing would happen. By the way, with the old points style pumps, the swamping resistor burning out goes unnoticed except for a greatly shortened points life do to a compromised arc suppression circuit without the resistor. Good luck - Dave
David DuBois

This thread was discussed between 02/07/2006 and 04/07/2006

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