12 replies to this topic

[Richard_]

Hello  -

 

My 1989  998  mini still has the original mechanical  fuel pump after 33 years, but only 25k miles.

It looks a simple job to replace  - Should I do it before I get stranded or do they last for ages?

 

 

Also the car conked out 1 minute after starting this week - apparently with no fuel delivery to the carb. Pump was working OK.

I think the float valve had simply stuck closed although it was moving freely after I got the float chamber lid off to look so its hard to say.

Anyhow the car is now working but is it common for the valve to stick shut?

I probably need to add a filter between pump and float bowl as the car often stands for weeks.

 

 

 

 

[richmondclassicsnorthwales]

Hi Richard

 

Fuel pumps can be good and strong for years, then they can give up the ghost, just as a new one been fitted now, you could

get 2 years, 5 years, 25 years - bit like a box of chocolates !!

 

Float valves can stick, again, young or old, and yes, when you take off the lid, won't find anything to talk of sometimes to find what made them stick.

 

If the valve keeps sticking and has not been touched in 20 odd year, it may need replacing.

 

Fuel filters are always a good idea too 

[cooperd70]

If it ain't broke.....

Also there is the possibility of poor quality replacement parts. I am under the impression that the mech fuel pump on my 1990 Flame Red is still the original. Hopefully it'll get me to L2B and back on Sun (300+ mile round trip)! 🤞🤞

I've got an inline fuel filter in the boot, but not in the engine bay.

[Richard_]

Yes i've known float valves to stick but only ever in the open position causing an overflow. 

That small issue has made me a bit nervous about the L2B !

 

(nearly 300 miles and a 4.00AM start - I must be bonkers!  ) 

[cooperd70]

We're ALL bonkers 🤪

[mbolt998]

I would be suspicious of anything with rubber in it after that amount of time (the fuel pump is basically a sheet of rubber).

[Richard_]

Anyone know if the diaphragm is able to be renewed in a 1989 998 car or does it mean a whole new pump?

[unburntfuelinthemorning]

I had a working pump from a 1984 engine but changed it recently with a new pump from SU just to be sure it could stand up to any ethanol in the fuel used.  Didn't fancy the ethanol finishing off the old one and then dispensing fuel into the sump.

[croc7]

Hello -

My 1989 998 mini still has the original mechanical fuel pump after 33 years, but only 25k miles.
It looks a simple job to replace - Should I do it before I get stranded or do they last for ages?



Also the car conked out 1 minute after starting this week - apparently with no fuel delivery to the carb. Pump was working OK.
I think the float valve had simply stuck closed although it was moving freely after I got the float chamber lid off to look so its hard to say.
Anyhow the car is now working but is it common for the valve to stick shut?
I probably need to add a filter between pump and float bowl as the car often stands for weeks.

Concern that the rubber diaphragm could fail is what prompted me to remove the mechanical fuel pump and install a Hardi electric fuel pump from Mini Spares. Glad that I did. If it fails on the road, easy to change.

[Richard_]

I suppose electric means the fuel can never enter the oil system but anyone had any good/bad experiences with the mini spares 'pattern' fuel pump? It seems a bargain:

 

AZX1818MS - Mini fuel pump mechanical pre 1990 cars and all 998 non genuine (minispares.com)

[leyland73]

Came into the garage one morning over lockdown to be greeted by a smell of petrol and the floor shimmering wet. My 89 Thirty had sprung a leak via the fuel pump. Car owned from new and 15k miles on the clock. Approximately 3 gallons of petrol had drained from the tank down to the level of the fuel pump. To say I was in a panic was an understatement, garage with 3 minis and a Morris minor in was reeking of petrol and I immediately opened both garage doors windows and walked away until the vapours had cleared.

New su ethanol resistant fuel pump was fitted along with new flexible fuel hoses.

Ive since replaced the fuel pumps on all my cars and renewed the flexible hoses with r9 fuel hose.

If it was my car I’d replace the pump

[unburntfuelinthemorning]

I suppose electric means the fuel can never enter the oil system but anyone had any good/bad experiences with the mini spares 'pattern' fuel pump? It seems a bargain:

 

AZX1818MS - Mini fuel pump mechanical pre 1990 cars and all 998 non genuine (minispares.com)

I had no end of trouble with one of them.  It just didn't seem to engage with the cam right no matter how carefully I installed it, it just wouldn't pump properly.  I put an old SU pump in and it worked perfectly and later replaced it with a new SU pump as a preventive measure.

[Stu1961]

You used to be able to buy new diaphragms for the SU mechanical pumps from Burlen Fuels (sole manufactures of genuine SU carbs/spares) though I'm pretty sure this is no longer the case, if it was me in your position I would buy the genuine article from Burlen, they now supply all their genuine SU mechanical pumps with ethanol proof diaphragms, they will also sell you ethanol proof hose as well. Gates are another reputable maker of ethanol proof hose, Moss sell it, its brand name is Gates Barricade