MG-Cars.net

Welcome to our resource for MG Car Information.

Recommendations

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGB Technical - Facet Fuel Pumps

Wanting to change my original fuel pump to a Facet (?) pump. Have a 74.5 MGB GT. Any feedback on that pump switch out, experience with the Facet and or what part number. Looking at NAPA to get the pump. Thanks!

JOHN
JW Colson

Why are you thinking of switching? Is there something youre unhappy about with the SU pump?
Ross Kelly

My original is malfunctioning; it continues to click and appears to be failing to supply too little or too much fuel to my weber carb. Poor gas milage, unable to maintain consitent idle speed etc. I will also rebuild my original for a back up. JOHN
JW Colson

No point in rebuilding your original pump if you aren't going to use it. The points in an original pump will film over causing the pump to fail from non-use.
If you fuel bowls are over filling, then the needle and seat in the fuel bowls are most likely dirty and not sealing. Make sure the float didn't develop a leak.
If the fuel line between the tank and pump is old and cracked, the pump will suck air not fuel and will keep clicking since the fuel line won't pressurize.
Kimberly

(Some) Facet pumps 'clack' all the time & drive you mad with their noise. Especially the small rectangular one. SU pumps are good for about 50,000 miles of continuous use but as mentioned the points foul up if left standing so if yoyu buy a new SU pump check/clean the points before fitting. If o'hauled correctly they only tick when fuel is being used. The other beauty of the SU is that they can always be 'fiddled with' to get you home. The Weber & SU carbs only accept up to 4 psi pressure so be careful which model you buy. For my money I would stay with the SU.
Garth
Garth Bagnall

John - Before you condemn the SU fuel pump, use the Fuel Delivery Troubleshooting Guide in the SU Fuel Pump Articles on m web site at: http://homepages.donobi.net/sufuelpumps/ to insure that the problem is actually the fuel pump and not something else. If the problem is isolated to the pump, consider having the pump rebuilt by one of the people listed at the end of the article. If you want to have a backup pump, get the Facet (part numbers listed in the article, Back Up Pump in the same section of my web site). and set it up with a switch so either pump can be selected. As Kimberly and Garth stated, a points style fuel pump is not a good choice as a back up pump due to the filming of the points over time. Cheers - Dave
David DuBois

"No point in rebuilding your original pump if you aren't going to use it. The points in an original pump will film over causing the pump to fail from non-use."

Yes they probably will but it is a moments work to tickle them up again. Much better that than be stranded with no spare.
Paul Hunt

I think what Kimberly and I were getting at and what (but I failed to state) was get the SU pump running and use it as the primary pump and install a Facet (or other electronic pump) as a permanently installed backup that can be switched in. From my point of view, there is nothing quite as bad as having to change out a fuel pump on a MGB by the side of the road. Cheers - Dave
David DuBois

"there is nothing quite as bad as having to change out a fuel pump on a MGB by the side of the road"

Oh yes there is, it's *not* being able to change the pump at the roadside, or fix any other problem at the roadside, and having to have a tow home that is much worse!

I had to change my chrome bumper pump at the roadside once (having ignored the warning signs once too often). The car was on soft ground so I didn't want to use the jack, and changed it with all four wheels on the car and on the ground.
Paul Hunt

We race a BGT with a Facet pump and it has been excellent for 2 years. It's the square looking one.
Richard Tinkler

Paul - Point well taken. Cheers - Dave
David DuBois

If you do decide to use the Facet pump, make sure it is the low pressure one (1.5-4PSI) AND, install it on an extra MGB transmission mount which happens to have the correct 2 bolt holes for the pump, and a single stud to mount, and acts as an insulator for noise.

Peter C
Peter Caldwell

Peter. Quite interesting idea. I have, in the past, simply bolted the Facet pump (back up pump) to the rear bulk head near the SU pump on my RB cars. Your idea sounds like a better one. Thanks.

Les
Les Bengtson

I use a square Facet pump and mounted mine on rubber blocks which definitely helped with the noise. It isn't too bad in my car which has no trim in it yet so I imagine with carpets and so on installed it won't be very noticeable at all.

Simon
Simon Jansen

I have used 100s of the facet low pressure pumps & in 38-39 years I have had 2 go bad after a lot of use! One went bad after 11 years on a 74 Austin merina & the other after 160k on my GT V-8. In my first 2-3 years of working on British cars only, I had 4-5 S.U. pumps go bad & from there the only S.U. pump I have, I sell on Ebay, & let someone else replace it in short order. I use the exhaust mts. off a late B that have the 5/16 studs out of each side & rubber mt. the facet pump with them & no rattle & thay go for ever!
Glenn Towery

I've nothing against the SU pump except it's price.

I've been running the square pump and a pressure regulator (both available off the shelf everywhere) since I've had my MG. 10 years and never a problem. I built an isolation mount and only hear it tick before startup on the coldest mornings.

If someone is giving away proper SU pumps sign me up, but I'll stick with my box til then.
C Holm

Mine has worked great for three years.
Randy Olson,Ithaca, NY
1977 MGB
randy olson

So far so good with my solid state SU pump, It must be about 5 years now. i know that you lose the built in "disaster recovery" of the original points system but after this much service I have to consider I am ahead. You still get all the features of the SU such as the pump runnig for a while at start up when it gets the delivery pipe up to pressure then stops plus the pump rate on fast idle and when you put the choke fully in all of which contains a,ot of information about how your car is feeling this morning.
Stan Best

Ahead after just five years? I'd expect a points type to run much longer than that before getting problems. Keep counting :o)
Paul Hunt

The facet pump I have put on a car, was run 10-12 years, looked well used, pulled it off & put on my car & it is still there!!!! 6 years later!!!! That junk of a s.u. pump, if it goes 5 min. your lucky! A long time ago (50s) thay were not as bad of junk as thay are for the last 40 years. If you need to sit on the side of the road, use a S.U. pump!
Glenn Towery

Cobblers! I fitted a new SU pump to my roadster 10 years ago and haven't had a problem with it. Seven years ago I cleeaned and refurbished the points on the roadster pump and fitted it to the V8 when I got fed up with the crappy electronic pump causing intermittent fuel starvation and haven't had a problem since either.
Paul Hunt

A side question, I'm assuming the above discussion centers on replacing or using either style pump in the original position back by the battery box.

I have a Facet (brass square) but its mounted by heater fan at firewall, bolted right to the sheet metal, which sends a lot of sound through the glove box area when it clicks away.

I plan to relocate to battery box so the pump is pushing more than pulling.

I assume this is a good idea.

I'm also considering that when I do move the pump from front of car to center, I should do so with a new pump and keep the old one for backup.

I haven't given much thought to installing a backup inline with a bypass switch though.
R.W Anderson

R.W. Go back through the thread and find the link that David DuBois has posted. Over the years, Dave's tech articles have been hosted on several websites, including mine. Now that he is retired, Dave has posted his own website with all of his articles on it, allowing him to update them as needed and not have to go through others to do so.

One of Dave's articles deals with adding a back up fuel pump to the system and that would make a good basis for the project you are considering. I made the conversion on one of my cars and, while it adds a minor additional level of maintenance, my opinion is that it is a worthwhile modification. Especially on a daily driver or touring car.

As to the newer SU pumps being not as well made as the older ones, this may be true. There are quite a number of things which, today, are not as well made as they used to be. This includes the current production Facet pumps. I know of three Facet pumps, all purchased and installed within the last four years, which have gone out of service in less than two years of use.

In my own experience, I have had one Facet pump and one SU pump, both new, fail within a few months of installation. The SU was rebuilt and put back into use. The Facet cannot be rebuilt and had to be replaced with another new pump.

Les
Les Bengtson

This thread was discussed between 28/06/2008 and 10/07/2008

MG MGB Technical index

This thread is from the archive. The Live MG MGB Technical BBS is active now.