I have replaced the mechanical fuel pump on my 1.3 Rally S with a new one. Now there is fuel coming out of the glass bowl filter (Fispa) through a tiny hole in the very top. It's not much, just enough to keep the area "wet". Does the pressure need to be regulated? Are'nt all mechanical pumps designed to put out the proper pressure with out regulating?
Any insight would be appreciated.
Regards
Fuel "weeping" ?
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Huib
Re: Fuel "weeping" ?
You are quite right. The original fuel pump produces a constant pressure of about 0,3 to 0,35 bar which is the correct value for the Solexes.
However, it is a good idea to check the pressure at the same time you do an engine tune up such as valve clearance. Also check pressure if you put on a new pump. The new pump may be different from the original one.
The Gunson pressure gauge costs about 20 euro. It can also be used to measure inlet vacuum. If you buy two you can synchronize carbs with it as well.
Some carbs such as the Dellorto DHLB works best with a much lower pressure of 2 psi. In this case a regulator is recommended.
Throw the thing out (Your 40 year old pressure regulator may no longer be good anyway). Mount a plastic filter in front of the fuel pump. And if you need a pressure regulator, put a new one between pump and carbs
However, it is a good idea to check the pressure at the same time you do an engine tune up such as valve clearance. Also check pressure if you put on a new pump. The new pump may be different from the original one.
The Gunson pressure gauge costs about 20 euro. It can also be used to measure inlet vacuum. If you buy two you can synchronize carbs with it as well.
Some carbs such as the Dellorto DHLB works best with a much lower pressure of 2 psi. In this case a regulator is recommended.
Throw the thing out (Your 40 year old pressure regulator may no longer be good anyway). Mount a plastic filter in front of the fuel pump. And if you need a pressure regulator, put a new one between pump and carbs
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Stephan
Re: Fuel "weeping" ?
Throw the thing out!? I guess you mean the Fispa filter. OK my car is a driver but the thing looks so cool and period. Anyway I checked the pressure and its fine, 0,3 bar as you say. So I will follow your advice but I think I'll keep the Fispa some- where in the garage anyway.
Thanks for the advice.
Regards Stephan
Thanks for the advice.
Regards Stephan
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Brian Hilton
Re: Fuel
My Fulvia 2c Berllina was built before the pressure regulator/filters were fitted, so I've fitted a Filter King, I did fit an inline plastic filter but as I was pulling up a lot of sediment into the carbs even with this filter fitted, Idecided to fit the filter king before a round trip to Portugal of 3500 miles,this was fitted by the bracket supplied to the inner wing, & piped in between the fuel pump & the carbs, never looked back since & no further problems with sediment in the carbs.
Brian Hilton
Brian Hilton
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Brian Hilton
Re: Fuel
Hi Colonel,
You maybe right although I think the problem as was, no longer exists after last clean of the filter bowl, I have tried undoing the drain plug in the bottom of the tank as I've had a new brass gauze filter ready to replace whatever is in the tank, but the plug obviously hasn't been undone for years & is very tight,, I don't want to tear the boss out of the 42 year old tank. and as it's not causing a problem at present I'm working on the basis of "if it aint broke, don't fix it"
Brian
You maybe right although I think the problem as was, no longer exists after last clean of the filter bowl, I have tried undoing the drain plug in the bottom of the tank as I've had a new brass gauze filter ready to replace whatever is in the tank, but the plug obviously hasn't been undone for years & is very tight,, I don't want to tear the boss out of the 42 year old tank. and as it's not causing a problem at present I'm working on the basis of "if it aint broke, don't fix it"
Brian
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Florent
Re: Fuel "weeping" ?
Stephan,
I bought six month ago a Fispa filter to fit on my Aurelia and I had the same trouble as you have. As far as I can understand how the filter works, this hole is drilled to allow air to get in and out of the upper part of the filter where the spring sits but, if the thin rubber membrane cracks fuel will also get out through this hole.
I dismantled my filter and found a hard membrane, not flexible anymore and I think, but I just can't see it, that it has cracks.
I bough a sheet of thin rubber, fuel resistant, to cut a new membrane in but I can't go any further as my lathe is out of order at the moment and I have to fix it to remove the axle wich was press-mounted.
Florent
I bought six month ago a Fispa filter to fit on my Aurelia and I had the same trouble as you have. As far as I can understand how the filter works, this hole is drilled to allow air to get in and out of the upper part of the filter where the spring sits but, if the thin rubber membrane cracks fuel will also get out through this hole.
I dismantled my filter and found a hard membrane, not flexible anymore and I think, but I just can't see it, that it has cracks.
I bough a sheet of thin rubber, fuel resistant, to cut a new membrane in but I can't go any further as my lathe is out of order at the moment and I have to fix it to remove the axle wich was press-mounted.
Florent