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1956 Packard Caribbean convertible #1275. I am having this problem that I put in a new pump but the gas is not getting to the carburetors properly. Should I try with the electrical pump?

If you have any of these items, there have been problems in the past with each and worth a look. The 8" long flexible hose between the steel fuel line to the pump inlet brittle or cracked on the inside and blocking fuel, the pickup in the gas tank clogged or possibly a pin hole in the steel line letting pump suck air, vent in the gas tank cap blocked, and the ceramic element in the fuel filter clogged enough to only pass air but not gas. Of course, the carb itself could need some work, depending on what it's not doing.

The gas comes out of the gas tank fine, the problem is not enough pressure to get to the carburetors.

You should not need an electric pump. I have both but use mostly the mechanical pump on my Carib and it pumps just fine. Any chance the pump was not rebuilt properly and one of the valves is in backward or the diaphragm was stretched tight when the two halves were bolted together so it can't flex properly and deliver. The pressure out depends a lot on the spring inside pump pushing against the diaphragm when full. Is the arm on the correct side of the cam so it is operating the pump properly.

I did have the problem with the ceramic element on mine. You could blow air thru but the varnish had clogged the element so badly that gas couldn't deliver in enough quantity to keeps carbs filled.

Rosa, I started developing the same problem. Changed out ALL of my fuel filters, ran OK for a week and then started doing the same thing. When I removed the ceramic filter, she ran fine. Next car show I went to, I started looking under everyone's hoods and guess what? Not one single ceramic filter! There is something about modern fuel that just gums the ceramics up real quick. I have two inline filters now (they are both under the car, easy to get to, hard to see) I use the see through kind so I can more easily guage when to replace.

As HH suggests, I'd suspect a faulty pump, or faulty (leaking) rubber flex line. Have you tested the pump itself? You can easily do it before you mount it, just hold you finger over the inlet as you pump the arm, it should pull and HOLD a vacuum (suction). These cars perform quite flawlessly with just the mechanical pump, they seem to be immune to vapor locking and other fuel delivery problems that some of the older models had.

I still have the Carter ceramic filter, it's been in there for 12,000 miles over 15 years, never a problem with it, though I have cleaned it a few times. All my friends with the V8s still use the ceramic filter as well, no issues. But, when cleaning them, if you use compressed air and blow in the wrong direction you just further imbed the particulates into the ceramic matrix and essentially ruin it by closing the pores. When cleaning with compressed air, blow in reverse! Probably ultrasonic cleaning is the best.

Try removing the ceramic element from the filter housing and retry. Sometimes it looks good, but the filter element is clogged internally. If the fuel pump itself is still not pumping enough pressure, and you have verified that you do not have a pin hole in the steel supply line or a crack in the rubber hose, then the fuel pump was not rebuilt correctly.

It is possible that one of the internal fuel pump valves is not open and closing as it should and this would greatly reduce the amount of fuel pressure it is able to provide.

Another to test if the problem is indeed in the fuel tank, or the steel/rubber supply line is to run a piece of good hose from the pump into a stand alone gas can. If it then works as it should then you do indeed either have a clog in the tank/line, or there is a pin hole in the line that is causing air to get sucked in and reducing pumping pressure.

I agree with Kev, try removing the ceramic filter element as a first step. Next, you can do flow and pressure tests to see if the fuel pump is up to spec.

(o{I}o)