Packard Forum Index » General

Does anyone have any secrets to starting a 1929 Packard 8 with a straight eight and a Detroit Lubricator Carb? It also has an electric fuel pump.

My 1929 is a bear to start when it has set for a couple days. I can crank and crank the motor and it doesn't even attempt to fire. The only way I can get it to start is pour gas into three or four cylinders. Once it is running it runs like a Rolex watch.

I've tried adjusting the timing and using the choke while cranking the motor. With the electric fuel pump gas just runs out of the carb but the spark plugs are dry as a bone.

Don't you normally want to prime with the accelerator pump before starting?

I'm not familiar with the 29's as I have a '55.

For the up draft carb. Get a friend and some starting fluid. Set the choke and hand throttle, one guy runs the starter and the other the fluid.

I agree starting fluid is preferable to direct gas in the head. I had a similar problem with my 32 however I had the new Packard Carbs Detroit Lubricator 51 installed and it still was hard to start even with an electric fuel pump. The solution was that I had low compression mostly due to stuck valves but later found out cylinders were also out of round and tapered. You say the car runs good once it starts and mine did too but had 40 to 60 lbs of head pressure which is low even for these low compression engines like our straight 8's. I suspect no fuel is getting in the carb bowl or not feeding up into the combustion chamber hence your dry plugs. It will only pull fuel when it gets enough rpm's which you get from the direct gas feed into the head. You might check head pressure which should be around 80 lbs. Also the rpm's of the starter are important. I would check the battery and cables as that 6v starter needs all you got to spin the starter at the necessary rpm's to start these engines. It can make a big difference if you do not have large 0 or 00 size batteries cables for both power and ground. The engine just may not be turning fast enough to pull the gas up to the valves.

Most likely it's the carb since you're not getting fuel mix and the pump is delivering, if not too much. Without a pressure regulator, it's probably delivering too much pressure and overcoming the needle valve going out the overflow. I'd have to look in my motors manual, the Packard section I sent to Kevin to post years ago, so that should be on here.
These are notorious carbs, hand built, and require expert restoration, so better to not fiddle with it yourself. There's a guy making "new" repro ones, but at two arms and a leg X 10 price which is probably about right. Refer AACA posts on these carbs.
Two components here, the age of the item and the technology of the day. So it's not going to compete with a 2023 w/ FI/HEI. Since it's worse with down period, it's drying out and not re-flowing.
That's can be fuel tank/line issues or deposits. Some of these early ones had gravity or vacuum flow. Maybe why the electric is on it. Rather than fix them, many just by-passed the fuel delivery issues. They were meant for momentary use to get things rolling. I don't recommend that DIY approach. Just as complex tech troubleshooting can confound, simple can be a hair puller, as well, as it's not apparent why it won't work being so freaking simple. Fundamentals persist. Procedure over hunt and pecking.
As noted, the condition of the motor is also in play. But it's should start if it's getting the correct fuel/air ratio and spark. As it apparently does once things get "over the hump". Low compression is easier to fire than high, but a weak spark should be corrected.
I ran a >100k mi. SBC on 7 cylinders for years after the second cam wiped. So that part doesn't need to be perfect and if no noises or hard turning, it's bottom end must be sound. It becomes an issue at some 'EOL' point and usually economics of constant repair to keep it moving vs bite the bullet. They won't last forever without regular wear part maintenance. Intermittent use will always bring start-up issues.

Thanks!!

Keith

The electric fuel pump may be flooding the engine due to too much pressure. "Flooding" does not mean you would see wet plugs. You should never see wet spark plugs. You should never see fuel drip from the carburetor unless you have over-used the choke.
To start a typical updraft carburetor engine when cold, especially after sitting for days, or in colder weather, it is normally necessary to use the choke. Open the throttle part way, close the choke, then crank the engine for 2 to 5 seconds, then open the choke halfway and crank the engine. That will start most engines if everything is in good order. A weak or undersized battery or undersized, skinny, or corroded cables, or a dragging starter can kill the ignition system during cranking. That makes starting very difficult to impossible, but if the engine does start, it will usually run OK and may start easily once warmed up.
An engine can be well-worn and still start fairly easily

Good morning. We drive a 23rd series. We find OO cables with a second ground cable necessary, then a strong battery…and clean connections all the way to clean points make a Hugh difference. Recently Miss Prudence turned over slower than usual. A new battery with 800 cold cranking amps and she fired right up. Fast cranking to pull fuel, careful use of the choke…You machine sounds to me like weak battery as she does fine when primed and warm. Ernie in Arizona

I'm not a pre-waree. I have this motors manual that covers '30-'42. I share when people need info.
The list (103) does not show a Detroit carb being on the P's? But this site should be able to verify what you have is correct or not. Not me, just pointing that out.
Here's the Detroit write-up from the carb section which was not shared with P-info.

ps:It mentions a starting circuit, so that might be the one's that not functioning and letting gas go in, as it runs OK, after start, but just my guess. I've seen other early ones that have separate starting or vacuum idle that can be an starting issue. Probably needs a good douche/soak, cleaning, and adjusting, but enjoy today instead.

Attach file:

---

img102.pdf Size: 876.61 KB; Hits: 87
img103.pdf Size: 905.49 KB; Hits: 57
img105.pdf Size: 957.03 KB; Hits: 51
img106.pdf Size: 1,053.87 KB; Hits: 290