504 fuel pump

geodon

geodon

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Fellow Frogger
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Geelong
The ute is being a bit cantankerous. It's a 2L with the dual throat Solex.

Starts on full choke, runs fast then dies, rinse & repeat a couple more times then it's fine.

I've also had issues with the needle valve: sometimes it jams shut (relieved by tapping with the back of a screwdriver) & sometimes it jams open (fuel dripping out the throttle valve spindle) but I think that's a separate issue. The carb specialist who reco'd it is getting me a new valve.

Fearing debris in the tank, I installed an inline filter.

Now as I understand fuel pumps, they only go one way. So, if the filter empties after switching off, the fuel must be draining back into the tank. That can't be right! There would be a spring loaded flap valve on the delivery side that SHOULD stop fuel going backwards, yes?

It's a sealed unit so there's no repairing it I guess?
 
Nearly all Peugeot mechanical pumps are mechanically interchangeable.

The early ones are able to be serviced . Some have a priming lever.

I'd place a wanted AD of AF.


Or fit Subaru brumby electric pump.
 
Drop the tank, clean it out and buy a new pump. Process of elimination.
 
I'm not sure why but the 504 fuel pumps sometimes let owners down at low mileages. I think some of the original pumps fitted in the 1970's weren't up to standard. A broken speedo cable inner on a drill allows the fuel lines to be cleaned in place. New pumps aren't expensive and are a good investment.
 
Russell Hall said:
I'm not sure why but the 504 fuel pumps sometimes let owners down at low mileages. I think some of the original pumps fitted in the 1970's weren't up to standard. A broken speedo cable inner on a drill allows the fuel lines to be cleaned in place. New pumps aren't expensive and are a good investment.
Click to expand...

Yes. You're right!

https://www.franzose.de/en/Peugeot/504-604/Kraftstoffanlage-Zeboehoer/ANR72906/

Looks good:

1. hand primer
2. it comes apart & there is a kit for it
 
Could someone please elaborate more about fitting an electric pump ?
Location ?
How to eliminate the original mechanical one ?
 
Why would you want to swap over to an electric fuel pump?
 
Yeah....the modern ones are well-made and last a long time. Nice and simple...
 
An electric fuel pump is a nice upgrade, they are not expensive and are easy to install. And you can fill the carb bowl without having to crank the engine, this is a big advantage when the car is not used very frequently. Just use a blanking plate in the mechanical pump space.
 
Will the electric fuel pump produce excess pressure for the carburetor?

Or is it same pressure with the mechanical pump?

Or it doesn't matter the fuel pressure for the carburetor?

Ikenna351, Lion King - Monk.
 
I use Facet fuel pumps for carburetors

Ikenna351 said:
Will the electric fuel pump produce excess pressure for the carburetor?

Or is it same pressure with the mechanical pump?

Or it doesn't matter the fuel pressure for the carburetor?

Ikenna351, Lion King - Monk.
Click to expand...
 
Repco sell a fuel pump suitable for carbys , i.e. only about 3 psi , its a little cube , they are cheap and reliable but do make a tick tock noise when running . Best to fit a tachometric relay so pump stops when engine stops .
 
My understanding is that 405 with carburetors (Solex 34-34 Z1) had electric fuel pump, I think. But then, Peugeot Mounted a plastic container that look like fuel filter before the carburetor where fuel supply line entered, then a 2nd hose from the container act as fuel return line to the fuel tank, while a 3rd hose on the container takes fuel to the carburetor. So the container reduces the pressure of fuel from the pump getting to the carburetor directly.

What it means is, to convert mechanical pump to normal electric fuel pump from newer Peugeot models to 504 or 505 with XN1 and XN1A Engines, you will have to install that container, then introduce another fuel line to act as fuel return line to the fuel tank, then you modify fuel tank to accommodate the 2nd fuel line (return line).

My experience with the mechanical fuel pump on those Engines back then were positive. They are just as reliable as the electric fuel pump (they do fail eventually). But the electric fuel pump fails too. So, is it really worth it to go through all that to use electric pump when mechanical pump is still available? The conversion will make more sense if the mechanical pump is no longer available to buy. I do still see Valeo brand of XN1 and XN1A mechanical fuel pumps on eBay. They should last thousands of kilometers or some years before failure, I think.

But there is nothing wrong in trying something new or different, if one wants to convert to electric pump, but it won't be plug and play, unless maybe the low pressure electric pump mentioned above.

Ikenna351, Lion King - Monk.
 
The cheap little cube pumps work ok and don't need any special plumbing. Buy two and keep one in the glovebox....

You could leave the mechanical pump disconnected, but in place; or make a simple blanking plate for it.

I wouldn't fit a tachymetric relay as it breaks the big advantage of an electric pump -- that after the car has sat for a few weeks and the fuel has evaporated from the carby, you just turn on the ignition and wait a few seconds. No need to flatten the battery cranking the engine to get the carby filled up again. The tach relay is only a safety measure in case the fuel line is torn in an accident. E.g. 504 TI didn't have one.

Have fun,

Rob.
 
With the facet type electric pumps do they need to be mounted low in the engine bay so that fuel can gravity feed to them . Where is the best location for them .
Thanks Keith
 
keithm said:
With the facet type electric pumps do they need to be mounted low in the engine bay so that fuel can gravity feed to them . Where is the best location for them .
Thanks Keith
Click to expand...

I put it where the injection pump is located in the 504 Ti, in front on the bottom of the fuel tank.
 
From experience Facet pumps in the above location are noisy in the cabin.

A recycled Subaru brumby pump can be reclaimed from the donor vehicle with the resilient mounts, hose elbows, anti pulsation system and reservoir.

I fitted an inline fuel filter between the tank outlet and the pump inlet.


The only downside is the Subaru hose fittings are 8mm diameter.

Easily fixed with a coupe of hose adapters.

The attention to detail by subaru makes the pump silent in the cabin.

I fitted an LPG cut off relay to the pump supply to make the vehicle comply with road rules.

You need to power the pump off the starter solenoid to supply fuel whilst cranking. Once started the LPG relay will supply power.
 
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