Morris Minor Owners Club

I dont know what tepmerature it was today but late this afternoon and in heavy traffic (Watford Hertfordshire) I heard that familiar sound of the fuel pump doing machine gun impersonations and was glad to reach home without total fuel evaporation, did anyone else suffer the same today, obviously only south of the border as it doesnt happen north of it as we have been told many times.

I've had it a couple of times in the last 2 weeks but the old girl just keeps on going despite the pump doing a woody woodpecker impression on the bulkhead

Ah, so it's not just my car then! This happened to me a few weeks ago at the end of a long drive. It was quite a warm day if I remember rightly. It happened just before I was due to stop for petrol. It took a couple of goes to start the engine again afterwards too, as if the engine was flooded. I thought the car was broken, but obviously not!

I had that fuel pump noise on the way to the Isle of Wight trip some weeks ago. It is better since wrapping the fuel lines in kitchen foil. I understand that heat from the exhaust manifold combined with higher summer ambient temperatures can heat the fuel lines and cause fuel to vapourise when exposed to the relative vacuum of the fuel pump suck.

Better cure is a proper heat shield.

The reason for this vapourisation is that modern unleaded fuel is rubbish compared to good old 4- star. Modern petrol has a lower vapour pressure than the old fuels the Minor was designed for. Modern cars use a pressurised fuel rail as part of the fuel intection system, the higher pressure prevents vapourisation.

Maybe a way round this would be to fit a Mini style "push" fuel pump at the tank end, rather than the Minor "pull" pump right above the exhaust manifold where it can get hot. Or maybe get your manifold ceramic coated or wrapped to reduce the heat given off in the engine bay.

Phew, thought my fuel pump was on it's way out, now I know why

I fixed it on my 1275 by using the mechanical lift pump on the engine. I believe you can also fit one of these to a 1098....?

mine started doin it two week ago in hot weather and traffic, so anoyin

PSL184 wrote:I fixed it on my 1275 by using the mechanical lift pump on the engine. I believe you can also fit one of these to a 1098....?

I fitted a mechanical pump off a Marina some years ago, no fuel vapourisation problems since. Simple fit but you do need an engine block with the 'hole in the side' to fit it and a spacer.
Mechanical pumps have been discussed before
http://www.mmoc.org.uk/viewtopic.php?f= ... 5&start=15
I noticed that I mentioned mine was ten years old back in 2006 so now approaching 15 years in service with no problem.
Better get the spare ready.....

My fuel pump goes like a macine gun when I turn the key then calms down after a couple of seconds, it then does it intermitently whilst driving. It's always been like that since it was newly fitted a few months ago!

That's how it should be although mine only pumps once or twice unless the car has been standing several weeks.

We had problems with my friends traveller getting hot in traffic and vaporising fuel which I think we've cured by wrapping the exhaust with exhaust wrap.
Incredible stuff, you can put your hand on the bandaged pipe when the engine is running!
Didn't cover the manifold as cast iron isn't compatible for some reason.

Hasn't happened yet, thoguh she has stalled while idling in hot weather D:

The answer is to relocate the fuel pump lower down - on the engine bay floor would be ideal - or use the mechanical pump. It's warm enough up here these days Kevin - we may get that problem yet!

chickenjohn wrote: Better cure is a proper heat shield.

But do you know of one that works as the likes of Grumpies and others made heat shields in the past and none made any difference.

Why do you say that?
Have you tried them?

MarkyB wrote:Why do you say that?
Have you tried them?

We have had various branch members that have tried various devices over the years and none have made any difference, and I once purchased a car with the heat shield fitted and it made not the slightest difference.
The mechanical fuel pump is one option that can be fitted if the block has the opening but many dont, and also many owners like to keep the original fuel pump looks and prefer the electric pumps to the mechanical ones.
If there is something out there that can be proved to solve the problem can someone please let me know about it along with how it worked as I would be more than happy to have something that worked, and others of my branch would also be interested.

As I said earlier - drop the pump down to the engine bay floor - it's the 'sucking' that the pump is not good at - so if it gets flooded suction from the tank = no more problems.

You could always move 'up north'

The heat seems to be moving up north too! Lovely day at Moffat show today! And there hasn't been any worthwhile rain for me now for several weeks. I now spend more time watering the garden - than I do on Forums!

This happened to me quite a lot yesterday on the way back from the National. It was very very hot though.
What helped, I think, was to re-route the pump to carb hose around the back (right) of the carb rather than over the top of the manifold.