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Filter Regulator Q
Dick Axtell - 8/8/14 at 12:18 PM

Checked my spark plugs this morning. Look like my Xlfow is running way too rich. How should I adjust the Filter King fuel filter press regulator? (Apologies if this has been asked before).

Its one of these - Malpassi Filter King Racing/Rally/Motorsport Adjustable Fuel Pressure Regulator.

minitici - 8/8/14 at 12:41 PM

What carbs are you running?

Paul Turner - 8/8/14 at 01:17 PM

If you have Webers fitted the regulator should be set initially to about 3 psi. You then need to ensure there is enough fuel at high rpm in a high gear for a suitable time to avoid it going lean and melting your pistons, best done on a rolling road.

Just remember that on Webers the fuel going into the engine is fed from the float chambers and fuel from the regulator fills the float chamber via the needle jets. If the pressure is too high fuel will get past the needles, flood the float chamber and the engine will run rich or you will have fuel running down the carbs.

If you have bike carbs you need to junk the regulator and fule pump and fit the relevant bike fuel pump.

You can rarely set cars up by experimenting, you need some expertise and gas analysing kit. Take it to someone who knows what they are doing. Cheaper than a set of pistons.

Dick Axtell - 8/8/14 at 02:28 PM

Am running the originally fitted downdraft Weber twin-choke carb. Maybe I should dispense with the Filter King altogether? Fuel pump is 2nd-hand Facet.

Paul Turner - 8/8/14 at 05:27 PM

quote:
Originally posted by Dick Axtell
Am running the originally fitted downdraft Weber twin-choke carb. Maybe I should dispense with the Filter King altogether? Fuel pump is 2nd-hand Facet.



TDo not do that.

The needle valve in any Weber will only cope with 3 psi max. maybe 4 psi on a good day. All Facets (new or secondhand) pump at in excess of 5 psi. You will simply inundate the float chamber and have a potential dangerous situation. Remember that any fuel leaking will simply drip onto the distributor and since there are sparks inside there it is not a good mixture.

Since you are only using the original carb I would be tempted to remove the Facet and the filter king and fit a standard Ford mechanical pump. No need for a regulator. I used one for about 4 years with twin 40's and never had a problem. Only slight downside was it took more turning over when starting from cold.

K13JOB - 8/8/14 at 05:57 PM

quote:
Originally posted by Dick Axtell
Checked my spark plugs this morning. Look like my Xlfow is running way too rich. How should I adjust the Filter King fuel filter press regulator? (Apologies if this has been asked before)..


But surely the running too rich has nothing to do with the regulator, as long as the float chambers are kept topped up (and not overflowing) the richness or is down to the jetting not matching the state of tune cam/compression etc of the engine?

Dick Axtell - 8/8/14 at 06:21 PM

Thanks for all your advice. Will check out the old fuel pump - if I can find it.

stevebubs - 9/8/14 at 10:55 AM

quote:
Originally posted by K13JOB
quote:
Originally posted by Dick Axtell
Checked my spark plugs this morning. Look like my Xlfow is running way too rich. How should I adjust the Filter King fuel filter press regulator? (Apologies if this has been asked before)..


But surely the running too rich has nothing to do with the regulator, as long as the float chambers are kept topped up (and not overflowing) the richness or is down to the jetting not matching the state of tune cam/compression etc of the engine?


I would assume the same....running rich shouldn't have anything to do with the pressure regulator on Carbs on normal running.

[Edited on 9/8/14 by stevebubs]

Dick Axtell - 9/8/14 at 12:40 PM

Xflow comes from Escort GT, and has big valve head. D/d Weber carb came with engine, so I've assumed that its all standard. Still looking for the old, cam-driven, fuel pump.