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On demand fuel pump

On demand fuel pump

On demand fuel pump

(OP)
Hi
Has anyone hear fitted an on demand fuel pump to a vehicle
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=280584867117&ssPageName=STRK:MEWNX:IT

Well I have fitted one to a Ford Transit
I fitted it to the floor of the engine bay so it is not much higher then the fuel tank
It pumps fuel up into the injector OK
But when I put it through the original fuel filter that is level with the injector pump as soon as the filter has been filled no fuel come out at the IP
So I changed the filter for a new one thinking it was full
But the new filter is doing exactly the same

So I have a theory and was wondering if anyone thinks Im right or wrong
It is an on demand pump and will cut off a certain pressure for obvious reasons
And by putting it through the filter housing I am putting up resistance and increasing the pressure needed to pump the fuel to the point where it is great enough to cut the fuel pump off
Is this correct or am I doing something ells wrong
Has anyone fitted one of these before and how did your fuel   filter effect flow

Thanks
Batista230

RE: On demand fuel pump

You are probably quite correct in your assumption - this sort of pump was originally designed to deliver fuel for gasoline systems at low pressure, say 3-5 PSI, which was all carburettor float valve and fuel filter needed.

Your diesel fuel filter will have a significant pressure drop compared to the gasoline type and the pump is then reaching the cut-off pressure and will not resume pumping until the pressure decays sufficiently.

Check other models and types for a higher pressure unit, but also look at the flow delivered as some manufacturers may trade of flow for delivery pressure.

Stanadyne units may be better for you, for example, if you're in the USA.

Bill

RE: On demand fuel pump

I've used that exact type Facet pump on a Morris 1000 a few years ago.  It worked well enough, attached to the OEM mechanical pump mounting plate in the engine bay.  Cheap little pump (about $35US) and, yes it did stop pumping (eventually) with pressure buildup as high as 6psi on initial start up.  I'm not sure I would use it on my Cummins even though the box said it was for "gasoline/diesel up to 32 GPH"...I think I would choose something with a little higher duty cycle.

Rod

 

RE: On demand fuel pump

(OP)
I forgot to say that I fitted this to a truckmount carpet cleaner a few years ago
It was a 16bhp briggs and stration carboretor with an inline fuel filter
I did the job of getting fuel from the tank under the van and pumping it to the carb with no problems with restriction from the inline filter
They do advitise that these pumps will run up to 200 or 250bhp engine comanly used on rely cars
Thats why I bought it
mind you pumping a mix of kero and oils through it has not help with the risistance to to the higher viscocity
But those fuels used to work with the original macanical fuel pump that I think was driven of the cam so im told
I swaped another manual pump round and it did not pump the fuel so i think what ever drives the pump is gone
The electrical pump is plubed up in line with the macanical pump
When the van was running it lost power and not enouth fuel to keep it going so therefore with the engien turning over the macanical pump was not doing its job along with the electrical
I have now decided to scrap this van has it has poor compresion and wont bum start down a hill at 2 celcius
If tihs pump was up to the job I would of liked to keep it even though im scraping the van
As its a handy tool and could of been used for pumping oil
But if as quoted above it dose not pump through a filter houesing then its useless to me
I will see if the man will take it back but if not can you turn the pressure up inside the pump by any chance?
Rod your commis is a bit like my van it terms of engine but I think tihs is a mis described item


Thanks
James

RE: On demand fuel pump

James, those little Facet pumps are used commonly in the smaller IC engines in vintage racing.  They seem to be okay for the most part...I just prefer something a little better quality and with a better pump rate.  I use Carter rotary pumps...about three times as expensive, but...

This is the setup on my Mini Cooper race car.

Rod

RE: On demand fuel pump

Batista230 - is your Transit diesel or petrol?

Since 95% of these vehicles in the Uk have been diesel for the last 15 years or more, that was what I assumed.
Or, is it a 2.0 T88 or a 2.0/2.3 DOHC of more recent vintage?

My original response was based on a diesel installation.

Bill

RE: On demand fuel pump

Rod, you really need a subwoofer back there!

RE: On demand fuel pump

(OP)
Yes Bill
Its an ordanary diesel engine

The good news is the man will take it back
But I thought I would have a quick look inside before sending it bak
[IMG]http://ebayphotos.webs.com/transit%20forum/fuel%20pump.JPG[/IMG]
As you can see there is a spring in place
I wondered if I put a bigger spring in there would that increase the pressure at all
I know I used to do it on the bypass regulators off the pressure washers
Stick 2 x 5p pieces behind the spring and the pressure on the gage would go up

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