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Now my beloved 1950 Packard developed a new problem (she is very creative). When I drive it on the freeway at 65mph she suddenly cuts out (or stumbles) when going uphill. The engine catches quickly and continues. to run well. She did that twice in the last drive. Also she now is difficult to start, either hot or cold and when started drops a cylinder until warmed up. Based on the freeway driving issue I assume there is a problem with fuel feed, even though I had Chirco supply me a rebuilt fuel pump recently.

The first thing I tried was taking off the glass sediment bowl and looking at the filter. Both are very clean. The filter is relatively new (may 500 miles on it) and there is no sign of debris.

That was easy. Now what do you folks think I should try next? Does anyone know what pressure the fuel pump is supposed to deliver when cranking? I can take off the fuel line at the carb and screw it into a pressure gauge.

Dear Fred:

Missing/cutout under load is indicative of an ignition problem. Although, fuel starvation is the second choice.

You can buy a KD spark tester from Napa. You should have at least 20Kv of strong spark with the tester connected to ground.

Good luck with your car.

Does anyone know what pressure the fuel pump is supposed to deliver when cranking?

Minimum about 3.5 psi, max about 5 is typical of this type of pump. Although pressure shouldn't change with engine speed (though of course volume will), pressure is best measured with the engine running at idle, just insert a "tee" in the line and affix your gauge.

PS - Alternatively, there should be enough fuel in the carburetor run the engine at idle long enough to measure pressure witn the fuel pump outlet disconnected from the carburetor and just connected to a gauge.

Quote:
"When I drive it on the freeway at 65mph she suddenly cuts out (or stumbles) when going uphill."

Not enuf info. Does that mean that it only stumbles and cuts out at the BASE of the hill and climbs the rest of the hill just fine???? Or does it stumble and try to cut out thru the duration of the climbing of the hill????

It makes a difference. One is possible acclerator pump inside of carb problem. The other is fuel starvation under load or possible electrical.

BTW. Since it will sustain 65 mph (i'assuming for at least 5 miles) then highly UNlikely a fuel pump problem.

hi Fred,

This doesn't sound like a fuel issue, it's more electrical.

Start with a tune up, including points/rotor/condenser and a new cap....new plugs properly gapped. Even if you've done this fairly recently. Part of this will be resetting the timing (which I suspect is the real culprit here).

While you're under there, check all the vacuum hoses (esp. the vacuum advance) and make sure they're on, tight.

First, check the point gap. The point cam follower tends to wear an close them. After you get them set, reset the timing.

The consensus seems to be electrical (even though everything is new and has maybe 500 miles on it). I am off to NAPA to get the KD spark tester and see what it looks like.

Even though the electrical system is new, the fuel pump is also new, so I do not have any old part to blame except the carburetor. Also I realize that 95% of all carburetor problems are cured by fixing the ignition.

Do youself a favor, get a new flex line for the fuel delivery, one of the PAC regions made all of them going back at least to the late 30s, and they aren't that expensive (in Packard terms) Might not be your problem, but I like to eliminate all possibilities and have every link in the chain good. You might look inside your tank for sediment that could be clogging the intake, things like that happen in 60 years.

Do youself a favor, get a new flex line for the fuel delivery, one of the PAC regions made all of them going back at least to the late 30s, and they aren't that expensive (in Packard terms) Might not be your problem, but I like to eliminate all possibilities and have every link in the chain good. You might look inside your tank for sediment that could be clogging the intake, things like that happen in 60 years.