Packard Forum Index » Post-War (1946-54)

Hello,
My 1950 Custom 8 Packard was losing power when I needed it going up hill mainly.
After many phone calls, reading suggestions, rebuilding the mechanical fuel pump, the carburetor (twice), replacing the coil, rebuilding the distributor, replacing the distributor shaft bushing, adjusting the points to .017, replacing the filters, draining the fuel tank, replacing most of the fuel line with new line material, adding an electric fuel pump with a regulator adjusted at 5psi in line with the mechanical pump and also by-passing the mechanical pump, the car was still losing power when I needed it....
All fuel pressure measured ok. All vacuum measured ok at idle, but went down under power...the issue was a vacuum leak at the connection of the vacuum tube/carburetor base which drives and warms the choke. The other side of the tube connects to the manifold.
My mechanic disconnected the tube, and plug the carburetor choke hole.
At the same time he bypassed the mechanical pump using the electric one.
So far, after 200miles going up and down hill (including steep hills), the car runs very well and pulls really good when I need power.
However, as I have been testing the electric pump set up, it is still powered by an on/off toggle switch. So, I have to make sure that I turn the pump power off when I switch the engine off....
Is there an easy way/place beside connecting directly to the ignition switch on the dashboard to connect the pump so it shuts off when I shut the engine off?
Thank you for your suggestions.
J-P

I don't know if you are still running any of the original ceramic element fuel filters but that symptom is also present if the ceramic element is partially clogged with varnish. They look just fine and air and a small flow will go thru without restriction but there is still enough clog that heavier flow at higher speeds is an issue. There are also screens in the fuel bowl at the bottom of the mechanical pumps that can get clogged with rust particles and give the same symptom. The old flex hoses at the bottom of the radiator between the pump and metal line can harden and the inner lining can crack. Heavier flow can pull the cracked lining pieces out in the bore where they act like a flapper valve and restrict flow.

On 41-7 Clippers and 48-50 models, because of the hood release and emergency brake mechanisms, the GA terminal on back of the ignition switch is rather hard to access.

It would be best to go straight from the ign switch but in other years with similar difficult access and a direct feed from the ignition switch Packard frequently used the battery side terminal on one of the gauges to power accessories because the instrument cluster is often easier to reach than the ign sw. Even though the wire supplying the gauges is a 16ga, it is a short run so powering the fuel pump from an instrument terminal should also work on your car. If you do not already have an inline fuse for the fuel pump be sure to add one.

Here is a snip from the 23rd series wiring diagam. Any of the three gauge battery posts connected to the power Buss Bars should work. As you can see from the diagram the Buss Bars are fed by wire 22 (black with 2 blue tracers) directly from the ign switch GA terminal.

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It depends. This is the current best practice I could find. If the "e" pump is self/internal pressure regulating to <6 psig, then you can wire in a relay off the ignition hot lead and install a branched pressure switch, keep original, that accepts another switch to feed back to the relay that shuts it off when motors off = no oil pressure. The "how to" info is on the airtex pump site and comes with the pump. The relay powers the pump only when the key is on, and the pump shuts off when pressure is good. Power is off when the key if off. I ran a separate resettable breaker for the 12V pump feed. I put this in on the Cad last year after fighting bad mechanicals coming in from MX. They moved the factory down there a few years ago and changed design and have/had issues. I notified airtex, but not sure where it is now. As best as I could tell there was only one model like this for carbs. And it's louder than I'd like. I haven't got around to noise isolation. ps: that's part of the problem with asking for advice on the internet, etc. and not properly diagnosing the fault. But not all for naught. A good running mechanical will do the job just as well. They ran like that for decades as produced.

Thank you very much for taking the time to respond and for your suggestion. I will check tomorrow how to connect the pump with a wire behind the dashboard.

As far as the filters are concerned, I put new external filters, 100micron from the gas tank and 40micron just before the carburetor and bypass the mechanical pump with an electric fuel pump. However, the vacuum line out of the mechanical pump are still connected and works well to power the windshield wipers.
Thank you for your response. It is much appreciated.