OK here's a question for all you mechanic types out there. I am gong to use the fuel pump from my sierra donor running into a DGAV carb on a 2.0L pinto. Connected to the fuel pump with a bit of plastic fuel pipe is a strange looking pot that according to the haynes manual is some sort of pressure regulator / fuel vaporiser device. Can I bin it or is it important?
they allways cause probs so bin it
If you are using the Sierra's mechanical fuel pump you need this to return the fuel to the petrol tank when the float bowl is full on the carbs,
or something to replace it, otherwise you will have carb problems with pressure built up in the fuel line flooding the carb. It is more of a swirl pot
to even out the pulsing effect of the pump and is the best thing for the job. A longer pipe between the pump and carb with a 'T' piece
return might work.
yours, Pete.
Well that's confusing do I keep it or bin it? What have others done?
I have exactly that: 2l pinto, single fuel line to mechanical pump to weber dgav carb - no return line, no problems so far in 7 years of motoring. (I have copper pipe from tank to engine bay, braided rubber from copper to pump and same from pump to carb)
Gentlemen, thank you for your answers.
Geoff, they say that mimickry is the best form of flattery. Therefore Sir consider yourself flattered. 
[Edited on 3/4/2003 by paulbeyer]
Paul, some pictures now in the archive. It's a Robin Hood but the principle's the same.
I am also looking at this at present, my car has a 32dft carb from an XR2 with a fuel return fitting.
I was not sure about what to do with it as i have no return line to tank. after removing the top of the carb and taking the fitting out i found it to
be just a pipe fitting with a very small hole about .5mm connecting into the fuel supply side of the needle valve. The only purpose I can see for it
is to prevent vapour locks by providing a constant trickle back to the tank.I am going to block it off and if i have any flooding problems will try
teeing it into the suction side of the fuel pump.
Paul.
quote:
Originally posted by Peteff
If you are using the Sierra's mechanical fuel pump you need this to return the fuel to the petrol tank when the float bowl is full on the carbs, or something to replace it, otherwise you will have carb problems with pressure built up in the fuel line flooding the carb. It is more of a swirl pot to even out the pulsing effect of the pump and is the best thing for the job. A longer pipe between the pump and carb with a 'T' piece return might work.
yours, Pete.
Hi Geoff,
Just took a look at your pictures, they'll make a good point of reference. Is your inlet manifold pink? Not that it would be a bad thing, each to
his own and all that, just wondered what the finish was.
While on the subject of fuel etc does any one know if the fuel pipe needs to metal (steel or copper) for the SVA or can I use a hard plastic fuel line which is easier to obtain and fit.
I saw plastic fuel pipe go through SVA at yeading last year,so i guess its fine.
Yes, I have to admit to having a pink manifold. It was shabby silver when I got it. As I used the thinners on it to strip it, it dissolved not only the silver but also the red (primer?) coat below and went pink - so I spread it all out evenly and now its a sort of metallic pink which is actually quite neat.
Mine returns from the item in question to the neck of the petrol tank by way of a length of copper brake pipe with fuel pipe connecting it at each
end. On tickover the fuel return to the tank is more of a jet than a trickle. It surprised me how much was going back. It was obviously too strong for
the needle valve in the float. Teeing it off to before the pump sounds like a good idea.
yours, Pete.
quote:
While on the subject of fuel etc does any one know if the fuel pipe needs to metal (steel or copper) for the SVA or can I use a hard plastic fuel line which is easier to obtain and fit.
mk2 escorts and the like had plastic fuel pipi,fiat uno as well but that runs under the carpet and aint easy to remove
Plastic fuel pipe in three different sizes are available in horsham were I live at the local motor factors, Horsham brakes. I would have thlught most good factors would be able to get their hands on some.
I've tried poo loads of motor factors in my area but none of them can supply plastic fuel pipe.
I found this link on the web for fuel pipe for a citroen 2cv http://www.ecas2cvparts.co.uk/dept.asp?dept_id=133
is this the stuff I'm looking for and will it be SVA friendly.
Just to keep you up to date , I rang and spoke to a man in the SVA dept and he thinks !!!! plastic nylon pipe is ok, so have brought some to day and
fitted it to the car 8mm for the feed and 6mm for the return line
Dave
ps have just had a look at that web site seems to be the correct stuf but not sure if it is big enough depends which engine / carb(s) etc your
running
[Edited on 8/4/03 by westdown]
I've sketched what I believe Peteff has implemented as "Original?", is this correct?.
Which other diagram, A or B, represents what others have done?
Or does the regulator go after the fuel pump?
My set up is a pinto 1.8 with a mechanical fuel pump. If I'm going to T into the fuel pipe, how far back from the pump / regulator is
best?
Rescued attachment Fuel setup.jpg
i think mine is like pete says, it goes from the fuel tank to the mechanical pump at the front of the engine, then to the regulator, where it branches. one to the carb, and one straight back to the tank. this ensures a constant excess of fuel, never too little (flow goes up with revs)and never too much.
Joel,
Is your fuel system configured like this then?
Conrod and Geoff Shep seem to have done without the return and I've seen reference to putting a T into the system to take excess fuel to the low
pressure side of the pump. Does plan B reflect this?
Any feedback would be appreciated
Rescued attachment Fuel setup2.jpg
spot on with the first one. plan b may possible have problems with fuel being sucked from the regulator too powerfully, whereas if it returns to the
tank then it isnt sucked, if you see what i mean!
a bit like a short circuit maybe, fuel just looping round the return and back to the pump, with nothing going to the carb and nothing coming from the
fuel tank itself? not sure though!
[Edited on 8/10/03 by JoelP]
Im running a 2.0 pinto with one twin down draught webber, i have no return on mine either, i dont have a regulator though, just the standard mechanical pump, if you fit an electric pump do you remove the mech one and blank it off or just remove the feed from it?
I used the original swirl pot thingy on my 1.8 cvh ,that returns fuel to the tank,and gives a constant (hopefully ) supply to the carb.
With just the pump feeding the carb you could flood the carb ,especially over bumpy surfaces/or high revs(vibration).
Another option which we used on Karts when running an axle pump (mechanical) was to fit a Filter King fuel regulator, it can be adjusted, to give
constant pressure, I cant remember now but I think we used to set it to 44" head of fuel ,by running some clear pipe vertically up a
stick!!!!!!!!!!!!
cant remember what poundage that equates to.........
But there should a maximum delivery pressure for the carb needle valve ......................
Blimey Boffins'R'Us.........................