Fuel Vaporisation

[moggiegeek]

With the return of the hot weather the return of the fuel pump pumping like mad - reeated clicking soemtimes accompanied by what seems like fuel starvation. I've insulated the pump and fuel line from the tank with fireproof insulating blanket covered with reflective tape but the problem persists.
Things not done:
1) Insulating fuel line from pump to float chamber
2) Installing a heat shield between carb and exhaust
Does anyone have experience of the best way to get around this problem? what materials to use etc.I've heard of people using aluminium sheet for the shield as well as new ceramic products.
I will be installing a Kenlowe fan to increase cooling in traffic ( of which ther's a lot around our way!)

[bmcecosse]

The problem is caused by weak fuel pump action - possibly the filter screen is blocked - check it. Could also be just less than optimal fuel pump (stroke not correct) - not able to suck the fuel up, or indeed could be a partailly blocked pipe - inspect carefully in case it has been crushed at some point along it's length. Sure fire cure is to mount the pump lower down in the engine bay - or use a mechanical pump instead. Insulation etc is a waste of time - fix the problem!

[rayofleamington]

Unless you've been sitting in stop start traffic for an hour or so before this starts happening, then I can only guess you have a secondary issue that is making the situation worse.
Fuel vaporisation on its own is highly unlikely when the weather is ~10 degrees.

[Ratbag]

I've gone for a belt & braces solution to this & it's not re-occurred:
1. Facet 'push' electronic pump located by the tank outlet.
2. Pipe relocated from the bulkhead along under engine tie plate to forward of the carb.
3. Where pipe comes up to carb the pipe is insulated with pipe insulation.
4. Exhaust wrapped with g/fibre bandage its whole length.

Didn't cost a lot, and as a bonus the cabin is much quieter with less exhaust noise and also cooler...
I also reckon the mild steel back box should last longer as it's getting hotter, drying it out. We'll see on that one.

Phil.

[bmcecosse]

A pusher pump with flooded suction will completely cure it - but the pressure may be too high for the float valve in the carb.... Hope it's well protected under there!

[Ratbag]

A pusher pump with flooded suction will completely cure it - but the pressure may be too high for the float valve in the carb.... Hope it's well protected under there!

No pressure problems (chose the plastic bodied LP Facet).
Pump is just higher than the bottom of the tank, but lower than the outlet, and shielded by it's clever mounting bracket....

[Biggles1957]

I had some issues with my Series One Land-Rover (almost the same SU pump as the Minor) and after a LOT of investigations turned out to be the inside of the rubber fuel feed pipe from the pump to the carb breaking down due to 'modern' fuels so that a little flap of rubber could block the pipe. When you remove it and blow through it everything seemed fine so it took some finding I can tell you! On one of our Moggies it was a blockage in the metal pipe from the tank to the pump

[moggiegeek]

Hi i'm interested in the " clever mounting bracket" do you have a photo of the installation? What kind of pump is it and where might I source one?

[MarkyB]

Are belt and braces not enough?

[Ratbag]

Hi i'm interested in the " clever mounting bracket" do you have a photo of the installation? What kind of pump is it and where might I source one?

This is the pump (low pressure version, 1.5- 4 PSI) , although can't recall where I bought it from:

http://www.fuelpumpsonline.co.uk/facet- ... -907-p.asp

Sorry, don't have any photos - or the means easily to hand, but if you can visualise the bracket-cum-standoff bolted to the boot floor just ahead of the tank also curling around the pump as a shield....

[moggiegeek]

Thanks for that - seems a good solution. I take it you mean mounted externally below the boot floor?
also how did you connect the pump into the fuel line - using flexible hose and jubilee clips to the pump and unions provided or by proper unions and flaring the existing fuel line? thanks.

[Ratbag]

Thanks for that - seems a good solution. I take it you mean mounted externally below the boot floor?
also how did you connect the pump into the fuel line - using flexible hose and jubilee clips to the pump and unions provided or by proper unions and flaring the existing fuel line? thanks.

Yes - externally below.
Flexible hose & clips....