15 replies to this topic

[ac427]

My 1983 Mini HL is in pretty good nick but i have been thinking about the mechanical fuel and the effect today's corrosive fuel will have on it.

I believe Minispares sell a mechanical pump that can cope with current fuels.

Is it possible to change the mechanical fuel pump with spilling oil or should the oil be drained?

Is finding a 12v supply in the pump area easy if i move to an electric fuel pump or should it be mounted elsewhere?

Is there a blanking plate available for to cover the mechanical fuel pump aperture?

[dotmatrix]

you can change it without draining the oil

I have been running the minispares mechanical azx1818 fuel pump for years everyday year round on e10. no problem yet

[timmy850]

The best current mechanical pump is the genuine SU pump as it’s designed for modern fuels

If your oil level is above the mechanical pump hole in the block you’d have other problems to fix first! Yes it’s fine to remove the pump with oil in the sump

Most minis with electric pumps have them mounted on the rear subframe under the pump. These type of pumps like to push the fuel along a long hose, rather than suck through the line from the pump to the front. If you add a pump here you’ll likely need to run a new 12v switched wire for it

Blanking plates are available, or are easily made

[68+86auto]

It's best to fit an electric pump to the rear subframe instead of the engine bay as they aren't designed with much suction. Fitting it to the rear subframe also allows for more flow.

 

You could fit one designed for a morris minor to the engine bay as they fitted them there and the pumps are designed for that position.

[StefanMini]

I fitted an electric fuel pump from Hardi. I mounted it near the fueltank. I don't want to risk that I ruin my engine if the membrame in the mechanical pump fails. See the video on Youtube from Thomas classic and modern.
Also you can prime the carb with a coldstart with an electric fuel pump.

[absx2]

I have not given this potential problem any real thought and as I still run a mini daily and have a couple that only come out when the sun shines is fuel pump failure a common problem or something people choose to address before it is ?

 

I know first hand of fuel hose issues, because it says suitable for unleaded doesn`t mean it`s ethanol proof

[bikewiz]

I have not given this potential problem any real thought and as I still run a mini daily and have a couple that only come out when the sun shines is fuel pump failure a common problem or something people choose to address before it is ?

 

I know first hand of fuel hose issues, because it says suitable for unleaded doesn`t mean it`s ethanol proof

I just recently installed a Facet cube electric pump after a rebuild as I'm on my third mechanical pump in 12 years. So based on my experience the new mechanical pumps last on average 4 years or less. I believe the last one was in the car for three years with probably less than 3000 miles. We'll see how the Facet holds up to the ethanol in the gas over here.

[ac427]

@absx2 It was the video mentioned in the post above yours that prompted this post.

Before then, i had only thought about the rubber fuel pipes.

[Steve220]

@absx2 It was the video mentioned in the post above yours that prompted this post.

Before then, i had only thought about the rubber fuel pipes.

If you get a GENUINE AP fuel pump, and replace the hose for R9 rated, it'd be the cheapest/easiest solution.

[GT Jimmy]

My mechanical pump has just failed, my oil stinks of fuel. If all is good with a dry then wet compression test tomorrow I won't be replacing it with a mechanical pump. Was new 6 years ago, maybe 6000 miles

[alpder]

If you get a GENUINE AP fuel pump, and replace the hose for R9 rated, it'd be the cheapest/easiest solution.

I'll add "genuine AP pump" to my Christmas list. Might even pre-emptively replace my generic fuel pump with one now, as a matter of caution. Where best to buy one (and know you're getting genuine) please?

 

FWIW my experience of generic R9 pipes (on a diesel van) was that you'll get a couple of years, then they go porous - perhaps more easily detected on a diesel because of the strong smell of it. When removed, the inner rubber has lots of radial splits in it. Reading between the lines of pipe that is rated for "up to E10" kinda suggests that it's not really proof against ethanol. I mean, why would the percentage of ethanol in the mix matter: either the ethanol is dissolving the rubber, or it isn't. There's not really a middle ground where it's all fine because the pipe is only dissolving slowly due to low concentration. I now only use Cohline 2240 - which is rated for any mix of ethanol up to pure 100%.

Edited by alpder, 09 April 2025 - 07:52 PM.

[absx2]

@absx2 It was the video mentioned in the post above yours that prompted this post.

Before then, i had only thought about the rubber fuel pipes.

 

@absx2 It was the video mentioned in the post above yours that prompted this post.

Before then, i had only thought about the rubber fuel pipes.

 

I`m 90000 miles in with my original pump on my 83 engine and 100000 on my 1990 Cooper so I guess I`m on borrowed time but the failures do seem to be with replacement pumps and not so much the originals but all the same it`s probably a good idea .

[croc7]

My mechanical pump has just failed, my oil stinks of fuel. If all is good with a dry then wet compression test tomorrow I won't be replacing it with a mechanical pump. Was new 6 years ago, maybe 6000 miles

I was wary of potential damage to the diaphragm in the mechanical pump and went with the Hardi electric fuel pump offered by Mini Spares.  Great product.

[68+86auto]

I have not given this potential problem any real thought and as I still run a mini daily and have a couple that only come out when the sun shines is fuel pump failure a common problem or something people choose to address before it is ?

 

I know first hand of fuel hose issues, because it says suitable for unleaded doesn`t mean it`s ethanol proof

 

Without ethanol, they last a very long time. I have engines (not just minis) with pumps which probably have the original diaphragms in them and are working fine. If they aren't original, they must be at a minimum 20 years old.

 

I haven't run any of them with ethanol as ethanol fuel isn't even available where those engines are.

[ac427]

@absx2 It was the video mentioned in the post above yours that prompted this post.

Before then, i had only thought about the rubber fuel pipes.

If you get a GENUINE AP fuel pump, and replace the hose for R9 rated, it'd be the cheapest/easiest solution.

Thanks Steve, Is the Genuine AP pump an electric or mechanical pump?

Is it available through Minispares?