Im very bummed by the outcome of today I finally put the oil bath air cleaner on, for my car not to start(1950 cadillac) so i took it off primed the carb and started it. great turned it off added the filter back and it wouldn't start again. now I tried a few times I'm thinking whats wrong, then i realize i didn't turn the key to ignition, dumb move. so i turn it boom it starts but now its shaking no idea why. only guess is I added a bracket to the rear of my muffler for a clamp on connection once I get my tail pipe. could it be that I have no time to remove that piece tonight but its gonna bother me not knowing, or is it something more serious? i hope not, any input id gladly appreciate.
Thanks, Joshua
Joshua,
It's easy to confuse "cause" and "effect." I'd focus on your oil bath air filter. Is the geometry such that it's closing the choke plate? Is the metal container up against your ignition wires and perhaps causing the ignition spark to ground out, thus causing the shake? While the engine is running with "the shakes," try removing the air cleaner... if the engine settles down and runs right, you're closer to uncovering the mystery.
Quote from: James Landi on July 14, 2025, 07:05:35 AMJoshua,
It's easy to confuse "cause" and "effect." I'd focus on your oil bath air filter. Is the geometry such that it's closing the choke plate? Is the metal container up against your ignition wires and perhaps causing the ignition spark to ground out, thus causing the shake? While the engine is running with "the shakes," try removing the air cleaner... if the engine settles down and runs right, you're closer to uncovering the mystery.
Ill try that as soon as I have time today. could it be shaking because of the attempts to start it aswell? Because this is truly an all of a sudden thing.
Ok I went through everything and truly found nothing I could see, maybe it was a miss fire. Today I took the bracket off the exhaust and it all seemed much better. I put it back on again and I heard a rattling so I feel its safe to assume that I found where it's coming from but I still have 1 question I notice the car shakes when I give it gas in neutral with the parking brake on, is that normal? I haven't owned the car long enough in running condition to even remember nor know. Thanks as always
Check your firing order. You may have a couple of wires crossed.
No, the engine shouldn't shake when you advance the throttle. Could be several new problems that recently "developed." As big fins suggests, check the firing order... you may have inadvertently missed up the ignition wires, and while you're at it, make certain that the ignition wires are PUSHED down in the distributor and on EACH plug. It's easy to disturb ignition wires perhaps when you installed the air cleaner. I'd check the vacuum advance.They have a limited service life, and most folks never check them. It's easy to do... attach an 1/8 diameter rubber hose to the inlet on the advance, and suck in on the hose. With the distributor cap off, you should discern a bit of movement on the stator plate where the points are located. If you suck in and no vacuum is held, the advance is TOAST and needs to be changed! A bad advance does negatively affect sharp rpm acceleration. Hope this helps, James
Quote from: James Landi on July 15, 2025, 07:01:34 AMNo, the engine shouldn't shake when you advance the throttle. Could be several new problems that recently "developed." As big fins suggests, check the firing order... you may have inadvertently missed up the ignition wires, and while you're at it, make certain that the ignition wires are PUSHED down in the distributor and on EACH plug. It's easy to disturb ignition wires perhaps when you installed the air cleaner. I'd check the vacuum advance.They have a limited service life, and most folks never check them. It's easy to do... attach an 1/8 diameter rubber hose to the inlet on the advance, and suck in on the hose. With the distributor cap off, you should discern a bit of movement on the stator plate where the points are located. If you suck in and no vacuum is held, the advance is TOAST and needs to be changed! A bad advance does negatively affect sharp rpm acceleration. Hope this helps, James
Ill try that later today when I have time, thank you for the help. I hope its something simple. Is it normally something simple or could it be a serious fix?
Joshua,
In addition to Big Fins and James comments above I would suggest inspecting the motor/transmission mounts as well. The shaking while applying throttle (engine torque) may be an indication the motor/transmission mounts could be bad.
When you re-mount the exhaust bracket(s) back and the rattle gets worst you are now adding a secure mounting point(s) for the drive train so the rattle/shacking will intensified.
Quote from: J. Gomez on July 15, 2025, 08:52:05 AMJoshua,
In addition to Big Fins and James comments above I would suggest inspecting the motor/transmission mounts as well. The shaking while applying throttle (engine torque) may be an indication the motor/transmission mounts could be bad.
When you re-mount the exhaust bracket(s) back and the rattle gets worst you are now adding a secure mounting point(s) for the drive train so the rattle/shacking will intensified.
Damn, whats the way to check the monuts to make sure there still good? i hope it's not the mounts they seem like a pain to replace.
Quote from: Daffer on July 15, 2025, 09:07:01 AMDamn, whats the way to check the monuts to make sure there still good? i hope it's not the mounts they seem like a pain to replace.
Joshua,
Several ways;
a- Visual inspections on the condition of the rubber.
b- With the engine running (in P and Ebrake on) high rev the engine and see if it rocks while revving.
c- With a braking bar apply torque to each mount and check if the engine rocks on each side.
d- For the transmission you may need to jack it a bit to see the mount condition.
There may be other options from other members on checking them, also not sure how complicated would be to replace them if needed on your 1950.
Good luck..!
Quote from: J. Gomez on July 15, 2025, 09:30:48 AMJoshua,
Several ways;
a- Visual inspections on the condition of the rubber.
b- With the engine running (in P and Ebrake on) high rev the engine and see if it rocks while revving.
c- With a braking bar apply torque to each mount and check if the engine rocks on each side.
d- For the transmission you may need to jack it a bit to see the mount condition.
There may be other options from other members on checking them, also not sure how complicated would be to replace them if needed on your 1950.
Good luck..!
Thank you for that! ill be trying all the suggestions when I get home today. Hope I figure this out today, will give an update
Update: I need to buy an adapter to fit a rubber hose to the vacuum advance to do the test "James Landi" suggested but i dont have time to go get it today. But I did start it again and made sure all the spark plugs and coil lead wire were all tightly in place which they were. I started it and all is good at that point but I lightly rev it and it starts rumbling and I start hearing the exhaust rattle. I gave it 3 soft revs then did a normal longer rev and no rumbling just smooth. So I tried just doing 1 big rev and at the beginning it rumbles then smooth. Could this possibly be a carburetor issue. Because after revving it the car starts rumbling when I let it idle like it wants to die out. Again any input is much appreciated I really wanna get this issue solved and im no car expert lol. Thanks
Quote from: Daffer on July 15, 2025, 05:32:21 PMUpdate: I need to buy an adapter to fit a rubber hose to the vacuum advance to do the test "James Landi" suggested but i dont have time to go get it today. But I did start it again and made sure all the spark plugs and coil lead wire were all tightly in place which they were. I started it and all is good at that point but I lightly rev it and it starts rumbling and I start hearing the exhaust rattle. I gave it 3 soft revs then did a normal longer rev and no rumbling just smooth. So I tried just doing 1 big rev and at the beginning it rumbles then smooth. Could this possibly be a carburetor issue. Because after revving it the car starts rumbling when I let it idle like it wants to die out. Again any input is much appreciated I really wanna get this issue solved and im no car expert lol. Thanks
From what you described I think it could be a carburetor issue. My first guess would be a worn out accelerator pump.
Quote from: Jay Friedman on July 15, 2025, 05:53:34 PMFrom what you described I think it could be a carburetor issue. My first guess would be a worn out accelerator pump.
Interesting, I can see that though. I've had issues with my carb so im glad someone is backing up my theory. Hate to take the top half apart again but id like to get this resolved. I have a new leather one so shouldn't take to long, I should've replaced it before since it came with the kit but I was worried about issues a new one could cause. Thank you
A '50 Cadillac has a Carter WCD carburetor. If you look down the throat of the carb, you'll see 2 nozzles sticking out from one side of the throat and pointing toward the other side. On the other side are 2 little metal dots. After replacing the accelerator pump if you work the throttle you'll notice fuel being squirted from the nozzles toward the 2 metal dots. The metal dots are "targets" that the squirted fuel must hit. If fuel from one or both nozzles does not hit the dots, gently bend the nozzle(s) until it does.
Quote from: Jay Friedman on July 15, 2025, 05:53:34 PMFrom what you described I think it could be a carburetor issue. My first guess would be a worn out accelerator pump.
Update: I had time today and was able to take the top half of my carb off to replace the accelerator pump, honestly the process was very quick didn't even break a sweat. I oiled the leather to swell it because thats what ive seen, i then Put the bowl cover back on and tested it by pushing the lever up and wow did it spray, way better than when I tested the old one. I completed putting it back together and started the car, it rumbled at first like less than 1 second then all was smooth! I revved it multiple times and all was good even tried it with the air filter on, i swear its never felt smoother. All is good right now I dont wanna jinx anything but I wanted to give an update, thank you to everyone for you suggestions and thank you Jay Friedman!
Good deal!
Thanks for closing the loop.
Now go out and have fun.
Thanks for reporting the results. I'm sure this thread will help someone who has this problem in the future. It was educational to me as I would never have suspected the outcome.