Here's an interesting video.


I think anything is as reliable as what maintenance it see's.
The Facet fuel pump requires a very fine filter just before the inlet (according to the video), don't change that filter, and the pump would fail.

I would ask, what are people doing to their SU pumps to cause them to fail ?

We had a P5 Rover as a family car and it was driven into the ground, totally worn out and rusted, but the SU pump never gave any problems, my Dad was not big on maintenance, he did something about it when things broke.
We had a Mini for some time too, the SU fuel pump was never touched.

Glyn, you know very well that an SU pump can be made non-polarity sensitive.

I'm not big on electronic and solid-state replacement items, they have left me stranded, I never know where the components are coming from and how long they're going to last, this goes for so called solid-state pumps.

I'm the other end of the argument.

 

Yes I know the SU pump can be made dual polarity. No one said otherwise.

But having had a global job & worked in the oil industry for over 40 years I also know the SU pump failure rate stats & they suck.

Just because you have not experienced something does not make it so. I stand by my comments well backed up.

All the fuel companies know this. More cars have stopped by the roadside due to SU pump trouble than any other of the era. And it has nothing to do with market share because SU's share is/was, in fact, low globally.

 

I have twin SU fuel pumps on my S Type. Never had a problem........................................... .until last week.

I went to start the car, turned on the ignition and there was no ticking. Thought nothing of it as sometimes the float cambers and fuel filter are already primed and tried to start the car. Nothing. Switched to the other SU fuel pump on the left tank and the pump ticked and the car started. I love the design of the S Type with twin tanks and twin SU fuel pumps.

Not had a chance to pull the fuel pump yet as I had work to do in the house but I can guarantee that it will just need the points cleaning and adjusting and it will be good for another ten years or so. I have three NOS SU fuel pump spares in my box of many parts that I bought with a job lot of Jaguar parts but have never had to take them out of their boxes yet.

 

That would be typical Rob. We are lucky we have dual pumps & tanks.

If I were asked the question as to what gives trouble in SU pumps I would answer in the contrary ~ the casing. It seems robust.

More wheel wrenches have been used to clout SU pumps than change flat tyres.

Keep your spare pumps. Don't even contemplate selling them. You will need one sooner or later. Maybe sooner.

The most reliable pumps globally are those that run off of the engine's camshaft pre fuel injection.

 

I meant to say Rob ~ ideal for your wedding sideline. ~ Get me to the church on time.

 

I would like to see if these electronic pumps would still be working after 20, 40, or even 50 to 70 years later.

 

Solid state either suffers infant mortality or almost has indefinite life other than some types of capacitor that are easily replaced. Anyway the SU mortality rate is awful. Something the Petroleum industry is well aware of and you cannot contest.

In fact if you suffered what Rob just has I don't think you would admit it. If a Hardi failed on me I would immediately post it. SU's have nowhere near the life you claim unless unused in a box or car. They have always been troublesome & remain troublesome. SU pumps have a well earned reputation for being so.

Would you put an SU pump in an aircraft? I most certainly would not whereas a number of Facet pumps have FAA accreditation and some likewise don't.

 

Those of us with fuel injected series XJ models that inherited the twin tanks have none of the advantages of a redundant system, just a load of extra valves to go wrong. By coincidence, they maintain the tradition of responding well to a nicely judged blow from a wheel wrench or an adjustable spanner.

I agree that SU pumps aren't great, but I'm not sure we've advanced a lot. I've replaced several Bosch fuel injection pumps in my Daimler as they are hopelessly intolerant of dirt. For a while, I kept a couple of spares in the car.

 

Peter
In my S3XJ6 I have incorporated a filter prior to the pump as those Bosch pumps, as you say are intolerant of any dirt.
Glyn
Ref. Facet pumps in aircraft.
For about a decade I owned a Piper Cheroke 180 aeroplane serial no 28-2537 registered in Australia as VH-BHN

It had been modified with a FAA (Federal Aviation Agency) STC (Supplementary Type Certificate) to run on MOGAS i.e. motor car fuel as opposed to AVGAS which is certified aviation gasoline.
Apart from some minor plumbing changes the major part of the modification was to delete the old Bendix electric fuel pump running at 4 PSI and substitute it with a pair of Facet pumps running at 8 PSI.

The pumps were in parallel and could be individually selected. The higher PSI was to obviate "vapour lock".i.e. vaporisation at high temps and low pressures. 8 PSI was the upper limit for the carby float bowl
It was mandatory to have one electric pump selected and running for take-off and landing when operating on MOGAS. In addition, the fuel had to be petroleum based and not have any ethanol added

By the way the Lycoming 0-360 engine was originally certified to run on the old 91/96 octane blue coloured AVGAS which seemed to disappear around 1970.

If the FAA are happy to allow facet pumps to be used in aeroplanes then they are good enough for me

 

Being a mod on MBWorld with 20,000 posts, Merc suffer very little pump failure and have no fallback but I think the reason is absolutely excellent fuel filtration (Mann + Hummel who they work in conjunction with ~ 1 micron nominal 3 micron absolute). However they will usually go into limp home mode & get you home. Sometimes one has to give it to the Germans. They are fine engineers & the big 3 do a good job. If one were to criticise they sometimes launch things a little early before debugging. But that was mainly due to a decision on computer simulation. They have gone back to running the vehicles on the road in the harshest of conditions for millions of Km's & the problem rate dropped like a stone. Software glitches are no issue as your car is updated at every service & connection to a Star computer with a new flash.

Some complain about the German big 3 & problems ~ but one requires to sub segment the complaint & it's usually something minor from the convenience menu that is software corrected at your next service. They are highly sophisticated vehicles with more to go wrong.

 

Touche & absolutely Bill

 

I also added a pre-pump filter to my DD6. It preserved the pumps. I think it dropped out during the present re-build. Now all the fuel system is new. I've mentioned before that in the motor club of my youth there was a sequence of Facet into Minis, Minis old SU pumps into Imps.

I agree that the German companies are very good at detail design and also development. I feel that sometimes they fall short in what in the offshore oil industry we called the global performance aspect of design. Certainly, they can start with a totally rubbish design and turn it into an absolute gem.

 

As BMW did with Land Rover prior to the final Tata buy out and all the rubbish in between. Tata has been wise in not interfering in a proven process & leaving JLR alone. But Tata themselves makes a lot of crap.

 

Improving the details of Land Rover products (or simply stopping the details from falling off) was a super human achievement. Unfortunately, it didn't take LR long to return to their old ways after BMW departed. I appreciate that beneath all the failings LR have potentially good cars, but I don't understand why their sales figures don't collapse. But then, I don't understand why so many people buy 4x4/SUV/off roaders.

 

Yes ~ their vehicles have a poor reputation in SA vs.Toyota, Benz etc. But JLR vehicles are certainly better than they were. Freelander 2 was one exception but only due to Ford & FL1 was such a poor vehicle to start with. They had to get FL2 right.

Their market share is poor here while Toyota & the German big 3 are at the top of the sales list. Granted some due to Brand Strength. Lexus has a hard time in our market & they come fully loaded. The Brand just never took off.

The 3 pointed star has almost God like status in Asia.

 

So what goes wrong with an SU pump, poor design, or lack of maintenance ?
Personally I think lack of maintenance and or lack of use, and even storage, owners don't seem to realize that the points and condenser have to be replaced at what, 10K or 20K, just like the points and condenser in a distributor.
When things go wrong, it's the pumps fault, it's not a modern car, even modern cars have their problems and leave the owners stranded on the side of the road when the electric motors brushes have failed on the fuel pump.
Lack of maintenance _ the MAF sensor needs cleaning, fuel filters, air cleaners, spark plugs and wires. People drive them until it quits and blame the car.

I'll give you this, the diaphragm becomes hard and crusty from lack of use and the electromagnet can't overcome the stiffness of the diaphragm and it won't work, or improper storage in a non-heated garage, and the points are so oxidized, they won't make contact.
When I belonged to the RR club, there were cars that were looked after from day one, mainly because they were expensive coach-built cars with very little milage on them, they changed owners as the previous owner passed away and the car was sold.
The car still had the untouched pump in it. If it was my car I would service the pump, but what ever.

I serviced the pump in the Jag shortly after I bought it some 20 years ago, it was still OK, but the points were worn a little crooked, and from the looks of it, they were installed crooked.

Which brings me to another problem, the DIY-selfer doesn't really know how to service it, even with the instruction right in front of them, they put it back together and it doesn't work, or it fails soon after because something was not done correctly _ and the pump gets blamed.
It's a fiddly job, that requires some patients and skill.

My luck I would get the electronic pump where it would fail shortly, I don't like electronic stuff for this reason, I can't repair it.

I will argue that there is nothing wrong with and SU fuel pump, it's the owners who are used to driving a modern car and lack of maintenance to the pump as to why they fail.
I would rather service a pump, then rely on an electronic one that may or may not fail early in its life.

 

My cousin, who is a very good driver (road, track, off road, rally), has tried everything else, BMW, Merc, Toyota ... , but stays with LR. She says the others are at least one of too slow, too clumsy, only for posing, unrefined, not serious off roaders. Basically, they don't hit the compromise she likes. To be fair, she's probably been very lucky with reliability.

 

Attitudes to servicing have changed. Consider all the grease points on our old cars. It also varied with make. Another cousin of mine bought an elderly R-R in the late 1970s, he was shocked by the cost of a main dealer service until he found what it included. They replaced everything that could be vaguely classified as consumable. He soon found a sympathetic specialist who was more optimistic about the life of items like coolant hoses and similar. In the day, SU carbs were dismantled, cleaned and rebuilt every few years. Apart from people like us, who does that or would do that now?

 

That's a bit excessive _ every 2 years, even back in the day.
One can clean it well enough just by taking the tops off the dash pots.
Even cleaning out the float bowls is pretty straight forward without having to remove the entire carbs.

Back then though oil wasn't very good, and the fuel was full of lead, so I guess service intervals were closer together; but still.

That probably would have been a Silver Shadow, that car is an absolute nightmare of over designed engineering requiring servicing, mainly to do with the brakes.
If RR could have simply ran some wires to a switch to get the job done, that would have been too easy; RR loved their relays and safety measures to keep the car from starting.
They put an inhibitor on the oil pressure sender to prevent the car from starting until there was enough oil pressure.
The weakener system gave some troubles if the vacuum lines were not up to snuff, and the solenoids stuck open and prevented fuel from getting to the main jet.
It would not start in PARK because the switch was worn out _ difficult to work on and get at things.

There are posts over at the RR forum pages and pages long on these subjects.

 

Jeff, you got it in one. He started with a 2 door aluminium bodied Shadow. Later they called them Corniche and they became more valuable. In those days, they didn't cost much. He later swapped it for a steel bodied Shadow that was in better condition. He was the first person in our family to own my Mk2. He used to say the Mk2 was a better car than his R-R, but at that stage he'd had a couple of illnesses and PAS and an auto box were easier for him. I remember an occasion we had the Mk2, his R-R, his Merc SL, Vincent, Norton, Scott and BMW motorcycles lined up outside his house. His wife's brother turned up with his Hillman Avenger and gave us a half hour lecture on what a great car it was.