DavidN1930

Thanks for your input everybody! I think the idea of junk clogging up the sending unit is pretty plausible. The only thing that gives me pause is that when I've had the problem before my first thought was that was happening, and even blowing air through the line didn't seem to do much to rectify it. Sometimes it's been literally blowing by mouth back through the line, and nothing really changed. It might be that so much junk is floating around that it immediately clogs up. When I first started working on this car in 2017 the tank got some attention, but mostly in the form of throwing a bunch of nuts and acetone in it and swirling it all around to get rid of some of the rust, but it probably really needs to be opened up and blasted, if only to just remove it as a possible point of failure and help with peace of mind there. I'm also intrigued by the possibility that the vacuum intake valve on the vac tank might leak a little. It certainly didn't feel totally tight when I tried the the "close of the vent and try to suck through it" trick. I didn't think about the possibility that air might simply go around the edges of the seat, so I'm thinking I might put a little JB weld or superglue around the edge of the seat, just to be sure. I bought another tank assembly off eBay, which needs some serious cleaning but otherwise is in good knick. If all else fails I might try to fit it, but I need to try some other things first. Unfortunately, in the last few weeks I've started to hear a very slight knocking sound at startup and at high speed. I'm hoping that maybe it's just piston slap from some weak piston rings, or maybe just built up carbon. I did the "hold a brromstick to the engine and your ear" thing to listen to the sounds, and the closest I could find that sounded like the knocking noise seemed pretty high in the engine, so I'm reeeaaalllyyy hoping it's not any of the main bearings. I gapped the plugs a few days ago, some of which were pretty far out of spec, but I noticed a lot of carbon on top of the pistons and, presumably, around the valves. Gapping the plugs will help but I also adjusted the metering jet on the carb, which is adjustable. I think it was just way too rich. I'm also going to adjust the valves, which haven't been touched in who-knows-how-long, and I'll probably pull the head to do it, giving me a chance to look at the seats. And, having gone that far, I'm going to drop the pan, too, and double check to see if there's anything noticeably wrong on the bottom end. At the very least I'll get a chance to get rid of all that accumulated carbon, and make sure the valve train, which is pretty noisy, is to Packard specs. All that will take some time, as I'm on a shoestring budget and I've got to save up a little bit to purchase replacement gaskets. I'm hoping I can get to that in the next few weeks, but I'll be sure to update this thread later so this might help somebody with a similar problem in the future.

Whoops! Should be fixed now. The video is unlisted, but you should be able to see it by clicking on the above link.

Hello all, I'm having what I think are vacuum tank problems on my 1930 Packard 726 that I have yet to find an answer to. It's a pretty typical 8-bolt Stewart Warner type. I've scanned through all of the threads on here about others with vacuum tank troubles, but my problem seems distinctly different than almost all of those. The closest I have found was in this thread here. The situation described there is very similar to mine in that 1. There is no problem getting fuel into the vacuum tank. I have had that problem before, but I've fixed leaks and the like and it pulls fuel very well into the tank as can be seen through an inline filter. 2. There doesn't seem to be a vacuum leak. The car idles very well, and especially when idling, the slight vacuum drag (I guess you could call it that) that the vacuum tank puts to the engine when the tank starts to draw fuel is only sufficient to cause a slight dip in the idle speed, which picks up immediately again after the valve closes. 3. The vacuum valve seat is not slipping. A few years ago I was shown a trick to use a punch to preen a bit of the pot metal over the brass seat, so it can't slip out. Before then I had the problem where the valve seat slips out, keeps the valve from shutting off, and fills the tank to the point that gasoline dumps into the vacuum line, but that fix solved it. 4. The lower tank is full of gasoline. Even after I start to run into troubles, when I remove the vacuum assembly and inner tank the lower tank is full of gas. 5. The atmospheric vent for the lower tank is not plugged. 6. The flapper valve on the inner tank seems to seat well. I've done the test where you press it to your face and try to breathe in to check the flapper action, and it seems tight. I've ordered a replacement just in case, but while once I was confident that might be the problem, I'm not so confident anymore. The trouble goes like this: The car starts and idles very easily from a cold start. After warming up for a few minutes, and starting the drive, the car will run excellently for about 5 miles, cruising easily at 45 and pulling up hills nicely. Then, quite suddenly, when running at speed the car will start to act as if it is starved for gasoline. It will rapidly lose power and it will cough and backfire when throttle is applied. The sediment bowl appears, when this starts, to have a pocket of air in it it, and bubbles can be seen running through it, seemingly coming up from the carburetor line. I've taken a couple vidoes, which I put together here (https://www.youtube.com/watch?v=pWD68lHuAyg). The car does not stall though, and will idle seemingly quite happily once pulled over. Recently, when trying to get to the bottom if it, I was able to repeat the process of driving about 5 miles before hitting that power wall again without shutting down the engine for longer than a couple minutes to fiddle with things, so I don't think it's related to heat. The other tricky thing is that it seems somewhat intermittent. I ran into this problem in October, replaced the gaskets for the tank, and it seemed to run fine. Then I ran into this problem again, and afterward filled a crack near the fuel inlet on the top piece, and replaced the gasket for the sediment bowl. I then drove it for a few hours, and a couple days later the problem came back. I don't think it has anything to do with the ignition, though I could be wrong. Has anybody had a similar problem before? Any clues as to what might cause it?