Fuel Filter/ Regulator 105 GTV 2000

[Tim Jobson]

Hi Guys,

This weekend saw a new battery and managed to turn the engine over and get some oil pressure, that was the good news.

I was probably hoping for too much to expect after flushing the fuel system out and squirting start you bastard in the carbys that it would start for me after 5 years rest.

After checking the plugs were still dry, I pulled the fuel hose off the carby inlet, cranked it over a number of times and did not get more that a thimble of fuel out it, so I guess the fuel pump needs to be replaced.   When taking the fuel pump and the fuel bowl assembly off, I noticed that the fuel filter body looks like some sort of regulator.


Can someone explain what this regulator is meant to do and do I need to take the top of this regulator to clean it, can it be tested or is it a rather large assembly simply to house a small fuel filter?

Cheers Tim

[1750GTV]

Tim,
I've attached a photo of the 1750 fuel filter assembly, it is the same as the one on the 2000. The only user replaceable bit is the filter, or at least it's the only bit I've ever replaced. I've never pulled the filter head apart.
According to one of the books I have it says - "The filter is mounted on the right hand side of the engine compartment. This filter has a built-in fuel pressure regulator, controlling the fuel flow to the carburettors. Every 8000 miles (12000 km) it is recommended to clean the filter or renew the filter element if necessary."
Hope this helps,
Chris

[Tim Jobson]

Thanks Chris, it is a rather nice little glass bowl the filter sits in so I will do as the book says.

I presume when I get a new fuel pump and crank the engine over you should expect to see a good squirt of fuel coming out of the fuel hose to the carbys?, when the fuel float in the carbys are shut where does the fuel by pass the carbys?

cheers Tim

[Colin Byrne]

Hi tim, the reg on top of the glass filter unit is not a necessity but it is good to have it there, so just replace the filter (if you can't get the correct replacement filter, in the past I've cut open a standard plastic housed filter and the paper element inside fits great!) and I've never had a problem with the regulating part either.  With a mechanical pump you should see a good steady flow of fuel, it won't be very powerfully as those pumps only produce around 3-5psi.

when the fuel float in the carbys are shut where does the fuel by pass the carbys?

When the float closes the needle valves it simple dead ends the pump, no return system at all.

[1750GTV]

Tim,
As Colin wrote, when the carby needle valves are closed by the floats, the output from the pump is zero.
Because the carby equipped fuel pumps are low pressure devices (unlike the Spica injected ones), when the outlet is occluded the diaphragm should have enough play in it to oscillate up and down without drawing fuel in from the tank or expelling it out to the filter. If the pump is not working, the diaphragm may be torn. I'm not sure whether these are available as a rebuild kit, but you should be able to get a whole new pump without much trouble - the UK suppliers list them at about $AUD45.00 plus postage so they should be available locally in Australia.
I've appended a photo of the common mechanical fuel pump used by Alfa.
Chris

[adriank]

Turin imports has new fuel pumps for around $70 (inc freight), albeit not exactly the same design of the in/outlet pipes as the original but they fit on the engine fine - you may need to move the pressure reg/fuel filter slighty so it all fits back togehter.

Only know this since my fuel pump died on Parammatta road last saturday, and caused some traffic grief

Adrian

[Tim Jobson]

Adrian, at least you can drive your car, mine has only got to the rolling stage, hoping to give it a test drive (down the laneway) this weekend! 
PS:   Did any blonde pull over and give you a hand!

Tim