Hi,
my car has an after market fuel pump. It is rated at 3 to
6 lbs pressure.
Could anyone tell me what the rated pressure on an SU pump
is please? I know its very low, but should I expect a 6 lb
pump to give problems with SU carbs? Would it overwhelm
the needle and seats and flood the carburettors?
thanks–
Morro
Melbourne, Victoria, Australia
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
In reply to a message from Morro sent Wed 2 Jul 2014:
I believe it’s 3-3� psi, Morro. I recently had problems with
carburetor flooding which were cured by installing a new fuel pump.
It was suggested that installing a fuel pressure regulator would
have accomplished the same result so if your aftermarket fuel pump
should cause flooding issues there is a simple and inexpensive
solution.–
The original message included these comments:
6 lbs pressure.
Could anyone tell me what the rated pressure on an SU pump
is please? I know its very low, but should I expect a 6 lb
pump to give problems with SU carbs? Would it overwhelm
the needle and seats and flood the carburettors?
–
Nick Saltarelli '68 Cdn mkt E-type S1� OTS, '54 XK120SE OTS
Niagara, Ontario, Canada
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
In reply to a message from N�ck sent Wed 2 Jul 2014:
In reply, I have webers which it turns out needs 3 psi or
it floods. I found this out by putting a fuel regulator
on. Since then the mileage has increased considerably and I
don’t smell gas when I drive the car or when I lift the
hood. The car is much smoother now so the fuel pump must
have been flooding the carbs and intake.
dave Collins series 2 fhc–
The original message included these comments:
carburetor flooding which were cured by installing a new fuel pump.
In reply to a message from Morro sent Wed 2 Jul 2014:
If you are looking at ‘off the shelf’ fuel pumps, there are
two varieties. They come in low pressure (2 to 3 pounds
pressure) or the more common 3+ pound ones. Our cars use the
low pressure ones. You may have to look around to find the
correct ones.–
Tom Hishon, 69 E-type 2+2, 69 E-type OTS, 85 XJ6, '03 X-type
Wasilla, Alaska, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
In reply to a message from Morro sent Wed 2 Jul 2014:
Hello,
I’m experiencing same problems with a MK10, same engine and
carbs. The SU pump AZX1319 gives 2.7 to 3.8 psi acoring
SU’s page. The old one, Lucas centrifugal from the MK10,
gave 2.5 to 2.75. I don’t experience carbs flooding but a
very bad engine running. The issue under my point of view
is that for compensate the presure increase from the pumps,
more float bowl need to be submersed, this means higher
fuel level on carbs and imposible correct engine tunning.
My provisional remedy has been to lover fuel level about
1/4’’, yes, a bit more tan 6 mm. This makes the diference.
The car revs up finely and has a smooth idle. I will see if
I put a pressure regulator or I just maintain the float
bowl lever as explained.
Regards–
JSR
sant jordi, 23 08757 Corbera, Spain
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
In reply to a message from creuse sent Mon 7 Jul 2014:
Another alternative might be to replace the stock glass fuel
filter assembly with a Malpassi ‘‘Filter King’’ which has a
built-in, adjustable pressure regulator. I used one on an
Alfa with Weber carbs and it was great.
As they are made in Italy they should be easy for you find
locally, or on ebay, or even here:…
In reply to a message from creuse sent Sun 13 Jul 2014:
Hi Cruese…the regulator unit the lister posted completely
replaces the original glass bowl filter unit.
I have heard good things, in that it also filters the fuel
externally so that sediment is visible in the bowl, instead
of hidden, like the original (MKX) setup.
In your case, I would certainly fit this–
The original message included these comments:
Thanks for your sugestion. One regulator for each carb?
The in-the tank pumps put out about 2.5, and this continued with the first external pumps, before being upgraded to 3.8lbs. In the tank pumps can be lower pressure, because they don’t have to self prime. It’s possible that Jaguar ran into a priming problem and uprated the pumps.Or they did it as a matter of common practice when they upgraded to viton needles. I’ve run my triple SU system as high as 6 psi, I think beyond that it’s possible to cause flooding. Here’s an interchange list that may help: