Hi, I’ve got a 53 Olds that I can get started with a little gas in the carburetor but when I press the pedal it does. If I just let it run it idles fine…only does when the pedal is pressed. Is this just a carburetor issue? Would rebuilding it fix it? Thanks
It’s possible but sounds like a fuel pump problem as well. Toss a coin.
Could be either a carb problem or a fuel pump problem. My wild guess is a carb problem, but it’s impossible to diagnose over the internet. I’m just guessing wildly. 
"when I press the pedal it does"
I am certain you meant Dies. This sounds like a problem that a carb rebuild would solve. Might as well replace fuel filter at the same time.
Had that problem once on an old jeep truck . It was the fuel filter .
With the engine off and the air cleaner off, do you see gas squirt into the intake when you pump the gas? If not, the accelerator pump is bad, rebuild the carb. But replace the fuel filter first, just in case.
1 Like
I had a similar problem with my 1978 Oldsmobile Cutlass. The problem turned out to be the fuel line. It had a hole in the line near the gas tank. Disconnect the fuel line from the carburetor and.direct the line into a.container. Crank the engine with the starter. If you don’t get a stream of fuel, work back towards the tank. If there is a hole in the line, your fuel pump is sucking air. Remember, Carburetor is a.French word for “leave it alone”. Save yourself the grief.of.doing a carburetor rebuild and not have it help. Also, be.certain it is actually a fuel system problem. I was fooled once by a.weak spark. It would ignite the overly rich mixture when gasoline was poured directly into the carburetor, but wouldn’t ignite the normal mixture. Unless your Oldsmobile has been changed to an electronic ignition, you have the old ignition points and condenser.
1 Like
Good points @Triedaq - we really need a lot more info. Was the car running fine recently? Has the ignition system been tuned up lately?
So, I just recently bought the car. The guy I bought it from told me that it ran fine but it needed the carb rebuilt. The ignition system has been redone at some point in the past as the plug wires and distributor do not look all that old…not brand new but not old if you know what I mean. My first thought was the full filter as well, but since it will continue to idle after you crank it I discounted that as it is getting fuel from the tank.
Pretty easy to just do a fuel pump test on it to see if its putting out or not. The only mechanical fuel pump I had go bad would come off idle fine but hard to get any performance out of it so it would starve on the highway.
So I’m voting carb or filter which should be done at the same time. Those carbs can leak from the bottom and empty the fuel bowl so you have to dump gas in. The other thing is those floats (not sure if they used the composite then or still the brass floats) can develop a leak and get filled with gas and that would give you a flooded condition which could flood the engine out coming off idle. Also the accelerator pump is just a piece of leather that regularly wears so when you step on the gas it won’t shoot gas int he carb and you can get a momentary stumble. Of course the thing could be all gummed up to or not the proper parts for current fuels. So yeah, after the quick fuel pump test, I’d be going through the carb. Back in the old days, we used to do it about every 5000 miles anyway for a $10 carb kit.
Have you checked the timing and dwell? You’ll need to do this in the near future, anyway. If I didn’t know the points were near-new, I’d replace them.
Does it have an automatic choke and is it working properly? Pressing the gas pedal once to the floor and releasing should set the choke if it is an automatic. Remembering a thread, poor starting, and that piece of knowledge was not in the car owners arsenal.
The problem with trying to diagnose a problem of this nature on a car this old is that there are so many things that can cause this just on the carburetor. If the accelerator pump isn’t operating properly, when you press the pedal the engine will starve, if the float isn’t floating anymore the float bowl won’t have any control over the fuel feed into the carb throat. If the jet(s) is/are plugged from varnish and gump, if the linkage is sticking, if there’s a vacuum leak, etc. etc. etc.
This one really needs a hands-on look-see.
1 Like
“The guy I bought it from told me that it ran fine but it needed the carb rebuilt”
Seems like the previous owner knew what the problem was. Still say rebuild carb and replace fuel filter and go from there.
2 Likes
Nice catch.
Y’know, I’ve successfully rebuilt a few carbs over the years, but there are many out there who would rather just buy a replacement carb. This option may be the wise way to go. Unless, of course, you’re trying to keep it all original.
No replacement carb on Rockauto, just a rebuild kit. Could take some looking to find one…
Have you tried to open the throttle very slowly to see if it will gain RPM? even if the accelerator pump is bad, it should be able to pick up speed slowly.
I’m betting on the accelerator pump drying out, they were known for this, especially if they sat around a lot. The carburetors needed a good cleaning and new gaskets every couple of years anyway.
They also need new plugs, points and condenser about once a year or 10k miles and an oil change and lube every other month or 1500 miles. Cars were high maintenance back then.
You need to get a timing light and dwell meter if you plan on keeping this car.
BTW, 2 barrel or 4 barrel?
I’d like to keep it all original. I’ve found replacement carbs on ebay but I have bid on any…150 sounds a wee bit high versus the rebuild kit.
It’s a 2 barrel.
That’s an easy rebuild.