I’ve got a '62 MK2, and I’ve decided to fit the Malpassi pressure regulator w/filter - the car’s been spewing gas out the float vent tubes, and fitting a new SU replacement pump (the car came with a generic pump rated 4.5 to 9 lbs.) hasn’t addressed the issue.
On their site, there’s a number of models/part numbers, but no way to know which one is best suited to fit my car…also, since there’s no gauge on the unit, I’m curious how one knows what the output pressure is.fitted one, and if so can you supply me with this info?
Actually, if there’s any other supplier of a unit that meets this criteria, I’m all ears!
Fwiw, the carbs are properly sorted with all the correct components, and two different types of “use only these” float needle/seat assemblies have been tried, with two different float heights tried as well…we’re down to the two most common causes of fuel being blown out the overflow pipes - faulty, dirty or mis-adjusted float needle(s), or excessive fuel pressure.
Depending on the model, an SU HP pump will provide 2.7 to 3.5 psi fuel pressure which is suitable for HD6 and HD8 carbs, with no pressure regulator required or normally provided. Volume is 15 gph which is about 1 quart per minute. Which SU pump have you installed?
An alternate pump providing 4.5 to 9 psi would need a regulator but that should no longer be necessary, and fuel leaks from vent tubes are more likely valve or float related as suggested above.
Fuel pumps should be 1.5 to 3 psi for our cars. Since you already have this pump goes with the regulator unless you can make a return to the vendor for an exchange. My monster 6.6 liter 400 CI GTO only takes 5psi or you flood the needles and everything goes wonky!. Keep us informed
I have this filter regulator on my cars as the new SU pumps I bought were all in excess of 3.5 psi. First thing you should do is measure the pump output. Please also confirm you have the correct washers in the correct sequence on the float bowls.
My problem only started when I fitted the new fuel pumps.
As I said, this was on an XJ6 with HS8 carbs. The fuel pumps are the submersible AC Delco type, so not SU. The output pressure is not adjustable.
The needle vales worked perfectly with the original pumps.
When I did test the output pressure, it was too high, so that was causing the overflowing.
My feelings are that the modern replacement parts are pretty poor quality. Not only was the pressure too high, but they are much noisier than the originals.
I’ve had difficulties with numerous replacement parts over the years, and it seems that it’s not getting any better.