Packard Forum Index » Pre-War (1899-1942)

TX Goat and Digger Dave,

Thank you both for your responses, these will be very helpful as I try to work through these issues. It may take me a few days before I can start trying these different suggestions, and I’ll let you know how things go, but at wanted to make sure to thank you both for your responses. Also Digger Dave, to answer one of your questions yes it is an updraft carburetor.

Could it be something from that damned ethanol "gasoline?"

I only use ethanol free - not abundant but still available if you know where to look here in Colorado.

If you have good pts, coil and condenser, three things I would also check out:

1-Pull all of the plugs and keep the wires attached to them. Lay the plugs on top of the engine. Have someone crank the engine. A good bright spark at the end of the plug indicates good wires and correctly functioning spark plugs. reinsert the plugs and move on to #2...

2-close the fuel value to the fuel pump and then remove the bottom brass plug under the fuel jet of the carb (closer to the radiator) and then the square headed jet hidden inside the plug cavity(you may need a 16 point socket). Make sure to capture the gas as it will come out of the fuel bowl and jet well. Once you have the jet removed ensure that there is no obstruction or small particle stuck to the wall or the jet orifice...

3-completely drain the fuel vacuum pump, then close the fuel valve to the carb and put new gas in the pump by filling the top of the fuel pump. Ensure that the brass fuel filter screen does not have any particles on it and make sure there is NOT another modern fuel filter somewhere between the gas tank and the gas pump (mine was tucked neatly inside the frames channel beam). Open the fuel value briefly to have it flush out your fuel bowl and then reinstall the jet and make sure you install a new crush-able copper washer on the brass plug.

Best of luck
GAR

Spencer, I had a similar experience with my 733. The problem turned out to be a coil. I had a couple of originals to play with and get me back on the road, but bought a new one from KM Lifestyle. I had to have the few inches that go into the under dash "holder" machined down a few thousands of an inch for a better fit. The case had lots of "meat" to work with. It works fine. Even so, I now carry a spare coil.https://mykmlifestyle.com

Gar, your post is timely. I had a friend I know through the CCCA come by yesterday and help me take a look and run some tests. After priming the carburetor we actually were able to get the engine running - and running smoothly at that - for several seconds. Which made us suspect that we are in fact dealing with some sort of an obstruction in the carburetor, and not the distributor / coils / condenser I’d suspected. We plan to reconvene today to attempt exactly as you suggest in your step #2, I will let you know if that’s enough to fix the problem. Fingers are crossed…

Thanks Pckrd 230 for the suggestions. For the moment I’m hopeful that it is nothing more than an obstruction in the carburetor that I might be able to fix this afternoon (see my post above). Still, I suspect that at some point the recommendation of this website may prove very useful - thanks for posting it!

Before disturbing the carburetor, be certain that adequate fuel is reaching it.

A problem in the fuel delivery system is as least as likely as a problem within the carburetor. If the engine runs well when you add fuel to the carburetor, it suggests that the carburetor is working properly.

I believe it's possible to prime a vacuum tank with a pint or more of gasoline, which ought to be enough to run the engine for at least minute or so, assuming the carbureter inlet is not clogged.

I think typical vacuum tanks have a drain valve on them, which should allow checking for the presence of gasoline in the vacuum tank.

If debris in the gas tank or fuel line is causing your problem, the vacuum tank would probably malfuntion before the carburetor, and debris would probably end up in the vacuum tank rather than the carburetor.

Any air leak in the fuel line between the vacuum tank and the fuel will play havoc with performance, especially in hot weatther. A plugged fuel tank cap vent is another possible trouble spot.

So some further updates on this. Yesterday I removed the plug at the bottom of the carb jet and cleaned what I was able to with that removed, including the high tech solution of a paper clip to scrape away and remove any gunk from the spray tube. After doing this it started and ran very well. For about 20 minutes when it promptly killed again.

So after charging overnight, today I repeated the process but more thoroughly, also removing and much more thoroughly cleaning the spray tube. Also got inside the float chamber, removed the float and cleaned inside there, and also took out and removed debris that was resting at the bottom of the glass bowl below the vacuum tank. After doing that I ran it again and it went beautifully.

Obviously though it seems that there is some crud somewhere in my fuel system that I will need to get out. It feels like the next step might be to see if the fuel line from the vacuum tank to the carburetor is all clear (I attempted to remove this but I couldn’t loosen it at the screw where the line meets the glass bowl - will try again soon), and then check the vacuum tank itself for contaminants.

Also a question - has anybody ever attempted to add a fuel filter? It seems if one were to do this, the the right place for this would be above the fuel line, right after the bowl outside the vacuum tank. Is this even a good idea?

The glass bowl probably is the filter. They usually have a fine mesh screen in them.

The vacuum tank may have collected some debris.

I've never worked on a vacuum tank so I can offer no advice except to proceed with caution and get all the information you can before doing any work on it.

If your fuel tank is shedding debris, you will most likely have problems from time to time until it is cleaned out.

Adding filters to non-pumped fuel systems often causes more problems than it cures.

I would want to be sure that any original equipment filters, screens, sediment bowls, etc are in place and working as they should.

All connections and gaskets on the suction side of the system must be air-tight, and the fuel cap vent must be clear.