Morris Minor Owners Club

Hoping I can tap into some of the knowledge available on this forum, I am about to fit a new electric SU fuel pump to my pick up which has been stood for about 20 years, I was thinking of fitting a fuel filter before the pump but as there is no pressure on this side will it cause a problem? will I ruin my new pump if dirt and debry from the tank and fuel lines gets to the pump? if I do fit a filter I will need to chop the fuel line and as this is metal need replacing, any advice would be appreciated, Regards, Steve

As you can see -a filter on the pump suction will cause a problem - leads to fuel vapourisation in hot weather. The SU pump (hopefully not an electronic one...) has an inlet filter in the base. But DO flush the tank and fuel line thoroughly before fitting the new pump.

Can you please explain the comment about the electronic pump does this refer to the S U type or another manufacturer as I was going to fit an S U Pump electronic version to my car

Fairly heavy bad reports of the electronic version - the old style points pumps seem to last a good 40 years or so - perhaps a new set of points. General view is -stick with points.

Agree with BMC. If it's been sitting for that long I'd at least pull the fuel tank sending unit and have a good look inside the tank. Flushing it out (and the lines) is a very, very good idea. I would fit a fuel filter (simple, cheap VW style clear filter) on the outlet side of the pump, between the pump and the carb. I don't know about the electronic pumps, but BMC is right, there is a filter screen on the original points type pump. That's good enough on the suction side.

Really is NO point filtering after the pump - the SU carb will happily deal with anything that gets through the filter on the pump.

I'd never doubt BMC, but when I did a quick service on my carb I found a couple of thimbles full of fine brown sediment on the bottom of the float bowl. The bowl is cleverly designed, in that the outlet port (passage to carb) is raised above the bottom with a couple of recesses on each side -- a sort of sump for crud. However, once those little sumps fill up (and mine were brimming) a slug of that gunk could very possibly clog the passage. I service the carb because I had what felt like random fuel starvation at speed, and I'm thinking that it was caused by a sudden passage of sediment through the carb. After cleaning out the float bowl (and adding the inline filter) there was no more hesitation and better acceleration.

I will admit that I didn't look at the carb until after re-doing the gas tank, and that the sediment may have accumulated because of the old rusty tank, but I figure the tank is going to get old and rusty again in time. It's also true that if you buy gas shortly after the station's tanks are refilled you're liable to get a load of dirt for your money. Another nice thing about these filters is that if you shake them out when changing you can see any evidence of water in the fuel -- and then deal with it.

The filter size of these cheapies is not particularly fine and they certainly seem to allow pump to keep up, so I'm thinking that they are simple and thrifty insurance

As an aside, I fitted one of the universal clear plastic in-line filters to the boys' 1100 last year, mainly as I needed to lengthen the pipe to fit the HIF carb, and didn't have a long enough single piece . When investigating his coil problems last week, I noticed the filter had started to leak at the joint lin between the two halves. Never had this before, just wondered if it may be another effect of the ethanol in our modern fuel not being compatible with some plastics/ adhesives etc? The filter was bought pre-ethanol days, but it made me think, especially as it was dripping onto the exhaust area

The SU easily copes with fine particles - there are no tiny passages to get blocked.

linearaudio wrote:As an aside, I fitted one of the universal clear plastic in-line filters to the boys' 1100 last year, mainly as I needed to lengthen the pipe to fit the HIF carb, and didn't have a long enough single piece . When investigating his coil problems last week, I noticed the filter had started to leak at the joint lin between the two halves. Never had this before, just wondered if it may be another effect of the ethanol in our modern fuel not being compatible with some plastics/ adhesives etc? The filter was bought pre-ethanol days, but it made me think, especially as it was dripping onto the exhaust area

The original VW Bugs came from the factory with those filters and no clamps. That was sort of OK with brand new fuel hose, but not in the long run. A fair number of them turned into torches on the side of the road. Dripping gas, hot air cooled engine = bad combination. The inlet pipe (brass) was a press fit into the carb, and they sometimes fell out with age. That was really exciting because it gave you full fuel flow all over the top of the engine. Another torch. I have to say that the MM technology has aged better than the Bug, all things considered.

Thank you all for your replies, it is an electric points type and the tank has been flushed, so I guess i will run with it and see how i get on, Thank you all again, its great to have a forum like this where you can get ideas, feedback and tap into other owners experience