Fuel pump woes

[Lizzy12]

I have a 1968 Morris minor 1000 . It’s a 1098 engine and over the last month or so I have had endless problems with the fuel pump and I am struggling to see the logic for such other then poor quality parts and bad luck .
When my old original pump on the car gave up the ghost and started to click non stop and overheat I purchased a new SU mechanical one to replace it.
Upon arrival It was duly fitted to the car and of we went for a drive only to find that 15 mins into the drive the car ground to a halt on a very ,very busy road . Pump was tapped and it sprang into life again it continued this way until we reached home . Ie jumping out of the car every few hundred yards to tap the pump so that it would pump fuel again and we could drive another few hundred yards. The Points were cleaned and that solved the problem for a very very short time .

The pump was removed and another new mechanical SU Fuel pump fitted . ( Points cleaned before fitting.) Only to find a few days in the same problem was back with the car cutting out . The Fuel lines were disconnected and flexible pipe from carburettor aimed in to a jar ,pump working lovely fuel nice and clear with no debris in it . Lines Reconnected , the car fired up for a little while until it didn’t run any more .

Fuel line disconnected again and air blown down in to tank with cap of to ensure it was gurgling properly ,and it was. Fuel manually pulled through lines fuel clear and no issues .
All earth and live connections checked ,cleaned and reconnected.
New vented fuel cap fitted just in case old one clogged.
2nd new mechanical fuel pump reconnected again ,where by it worked for a few days only to stop again . Each time it was tapped it would restart .

After calling a mechanic out twice to check to see if anything else was the cause it was again shown to be the SU fuel pump as each time it was tapped it would spring into life pump removed and lines again checked .

After removing the pump again and making a Frankenstein one with the bottom of one of the new SU pumps and the top of my Old original SU pump, I have a pump that is for now ,fingers crossed ,pumping fuel.

Does anyone have any suggestions as to any other possible cause for this failure of two new pumps or is it just bad luck and a possible bad batch .
The Fuel from the tank appears to be crystal clear when pumped into a jar . The line appears clear when blowing air up into the tank or when manually drawing fuel out of the tank .

I am totally stumped and getting Apprehensive of using the car in case the pump stops again .

[King Kenny]

It is just a thought... The only time I have had problems with point (distributor in this case) is the day after fitting new ones. They worked fine on the day I fitted them but failed the following day. I concluded that perhaps they were coated in a wax or oil to stop the metal parts rusting in storage and this protective coating creeped to the contacts during the rest period. I now spray new points allover with a degreaser before fitting. Maybe your new pump point have a similar coating. These pumps are a bit finicky but when they are working they work well. Best of luck with yours.

[svenedin]

I think King Kenny’s idea is a good one. This should not happen with a brand new pump but I think it is worth checking the points gap is correct too. Instructions on SU website (or they were) or SU workshop manual but I will try to find them and take a photo for you.

I have just realised I do not know how to PM a photo.....

Another idea is to convert the pump to electronic. You can buy a kit to do this and they come in Positive and Negative earth versions. Then the points are replaced with an electronic module. I did this and the pump works beautifully and is completely reliable.

Stephen

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[liammonty]

Have you checked the voltage reaching the fuel pump? It seems unlikely that several new pumps would be faulty. I had this problem 20 odd years ago and it was due to a poor power feed to the pump

[geoberni]

I have just realised I do not know how to PM a photo.....

It can't be done, you can't add an image as an attachment.
On the Messaging side, you can only insert the html Code for inserting an image link, i.e. the image has to be available somewhere else online.




Back to the original problem, I have doubts about 2 new pumps being faulty, and that a bodge hybrid pump is now working OK.
I know Lizzy12 said

All earth and live connections checked ,cleaned and reconnected.

...but there's checking and checking.
I'd be looking at earths and supply, to make sure the pump had a good 12v available. Has a Multi-meter been used to check for 12v across the pump.
I don't mean 12v at the Supply Connection on the pump to any old earth in the engine bay or even Battery Earth post, that could be 9v across the pump and 3v across a bad cable connection.

This could be a case of Wheel Tapper's Hammer.....

[Lizzy12]

Hi thanks for the replies so far and the very helpful information sheet which may prove most useful.

With regards to checking and checking yes it was ALL checked then double checked . Then to make sure in desperation I actually called the garage and the mechanic did a home visit .as car was so unreliable due to the fuelling .

The mechanic double checked connections and each pump when connected.
He even did a straight feed from the battery to the pump to ensure there was no bad electrical connection in my wiring causing the issue. There wasn’t and isn’t. The pumps will not pump consistently. Neither of them . Frankenstein pump however ,is currently the only one working . That is made up of the base part of one of the new pumps and the head part with the points ect from my old one ……. .

Points on new ones were cleaned before installation and after the fuel delivery problem started again . So no not making much sense.

[svenedin]

Ok well check the points gap as in the instructions above. If all else fails buy a kit and convert to electronic operation and you can forget about points.

https://www.morrisminorspares.com/fuel- ... th-p830653

Check you car's polarity if you are going to convert it. There are kits for both positive and negative earth.

Stephen

[Lizzy12]

Yes will do . The cars negative earth . But as soon as I have a free couple of hours I will be taking the pump into the workshop and making sure I go through all the info on the above sheets to see if there’s a solution to this problem in there .

[moggiethouable]

I dunno.
I had an intermittent fault that turned out to be the item shown under the distributor cap.
The engine would stop and would start again because the rocking of the engine when turned joined a broken cable, temporarily.
Can you hear the fuel pump ticking all the time ?
In other words, is it the fuel pump ?

[Lizzy12]

Hi,
Yes you can hear the pump doing its clicks and the car works, then no more clicks and car runs on what ever was in the float before it dies as the fuel pump is no longer clicking or delivering fuel . Couple of taps to the pump and it starts again for a very short time then stops again . Took the car out yesterday on the Frankenstein pump , made up from the bottom section of one of the new ones and the top (black section) of my old one , and so far so good pump working and no embarrassing road side stops . Just seems a daft and expensive way to get a fuel pump to work !

[myoldjalopy]

I dunno.
I had an intermittent fault that turned out to be the item shown under the distributor cap.
The engine would stop and would start again because the rocking of the engine when turned joined a broken cable, temporarily.
Can you hear the fuel pump ticking all the time ?
In other words, is it the fuel pump ?

That little wire can cause problems if it is breaking up, but the fact that the OP's pumps are temporarily revived by tapping on them does suggest it is the pump itself that is at fault....

[SteveClem]

Does anyone know why Morris decided to use the electrical fuel pump, when many cars of the era worked perfectly well using simple mechanical fuel pumps?

[geoberni]

Does anyone know why Morris decided to use the electrical fuel pump, when many cars of the era worked perfectly well using simple mechanical fuel pumps?

Probably because the SU fuel pump of the day was very reliable and in many cases has outlasted the engines of those cars several times over.
How often did the A Series Engine get regular maintenance, including stripping it down for de-cokes etc, while the pump just sat in the corner, quietly ticking away.


People carried spare mechanical fuel pumps, along with a load of other stuff when doing a long trip, because they were susceptible to diaphragm failure....

I think it's a bit 'rose tinted specs' to think the Austin decision to use the mechanical pump was any more justified than Morris using the Electrical one....

[ManyMinors]

I think you're right Berni. I've had more than 50 years of owning and running old Austin and Morris cars and can't say that either type of fuel pump has been any more or less reliable than the other. I think the OP is more than a little unlucky from what I've read here.

[kevin s]

The main reason manufacturers for using a mechanical one is they are much cheaper, the fact that the minor stuck with an electric one when the engine was available with a mechanical pump is probably a reflection on BMC/ Leyland having very poor control over cost, not investing in their products and infighting between the various sub companies than anything else, from what I remember every Ford and Vauxhall of the 60's had a mechanical pump.

[Dogsdad]

SU was owned by Morris privately until 1935 when it was integrated into Morris Motors.
This was why Morris Motors used the SU pump not a mechanical one.
Keeping things in house.

[rocco]

Just seems a daft and expensive way to get a fuel pump to work !

It does seem daft but it also explains why people mix and match the pump parts. I have such a Frankenstein, as you call it, but I didn't create him! I had intended to buy an SU repair kit but I'm not certain on which kit will suit it. I contacted SU/Burlen with photos to ask for this help to identify the monster but I didn't get any reply.

I'm now considering a Hardi electronic pump being as they are German made so quality should be good and they are cheaper too. I'll do this unless I can find a used and working SU pump in the mean time. I learned on another thread that bashing a Hardi when they stop working isn't going to help me.

[svenedin]

Just seems a daft and expensive way to get a fuel pump to work !

It does seem daft but it also explains why people mix and match the pump parts. I have such a Frankenstein, as you call it, but I didn't create him! I had intended to buy an SU repair kit but I'm not certain on which kit will suit it. I contacted SU/Burlen with photos to ask for this help to identify the monster but I didn't get any reply.

I'm now considering a Hardi electronic pump being as they are German made so quality should be good and they are cheaper too. I'll do this unless I can find a used and working SU pump in the mean time. I learned on another thread that bashing a Hardi when they stop working isn't going to help me.

Club spares sell refurbished SU fuel pumps.

I’ve had zero issues since I converted mine to electronic. However, if it fails it is not fixable by hitting it.

I use my car through the winter. My car does not have a winter rest. Points don’t like British winter damp very much.

The electronic conversion only alters the pump under the top cap by replacing the points pedestal assembly. Everything else stays the same. It still ticks reassuringly.

Stephen

[geoberni]

Just seems a daft and expensive way to get a fuel pump to work !

It does seem daft but it also explains why people mix and match the pump parts. I have such a Frankenstein, as you call it, but I didn't create him! I had intended to buy an SU repair kit but I'm not certain on which kit will suit it. I contacted SU/Burlen with photos to ask for this help to identify the monster but I didn't get any reply.

I'm now considering a Hardi electronic pump being as they are German made so quality should be good and they are cheaper too. I'll do this unless I can find a used and working SU pump in the mean time. I learned on another thread that bashing a Hardi when they stop working isn't going to help me.

Hardi pumps have a reputation of failing 'Hot', i.e. they not only stop working but then overheat, rather than just dying 'dead'. They also don't offer a service kit as far as I know.

I've replied over on your post about your pump, if you have any other questions about your one, let's continue the chat there.

[ndevans]

SU fuel pumps get a bit of a bad press, they have a bad reputation for failing because when they do fail, it is a showstopper. The reality is that they go on for years, decades even, pumping thousands and thousands of litres of fuel, with next to no attention. Eventually they decide enough is enough and sit down. I think they are actually one of the best engineered parts of a Minor.

It is worth thoroughly checking all the electrical connections, especially the earth. There should be an earth connection to the body of the pump- this can be a bit loose, and if so, may cause intermittent problems. The screw terminal that the live feed connects to is also worth checking for tightness, but not over tight, as that can damage the bakelite pedestal inside the cap.

I fitted an electronic pump from SU a year ago, but I'd have no qualms about using a conventional electro-mechanical one from SU.