1959 Long cranking before starting

[PaulB]

I know this is a problem for many old cars and there are probably several posts and dozens of reasons why an engine will crank and crank before it eventually starts. But let me share my situation and perhaps we can narrow it down. I had a professionally rebuilt carburetor installed and prior to that it started okay. The crank was not long, but not quick either. Maybe 10-15 seconds. Now it cranks for over a minute and never starts. I'm sure I probably flooded it. After about 3 or 4 minutes I try it again and maybe after 15 or 20 seconds it tries to catch then eventually does start.
Because the carburetor was the only recent change, I suspect that is where the problem lies. I had it timed too, but I have spark at the plugs and coil so pretty sure the problem is fuel not ignition. I did notice the choke is not fully close when the car is cold and wondered should it be completely closed or open a 1/4 to 3/8 of in an inch like it is now? My manual doesn't really address that. Besides the choke is there any other adjustment on the carb that i should look at. Or could i be looking in the wrong place and its something else. Oh, and when i try to start the car after its been sitting for a week or more, i press the accelerator pedal twice then leave my foot off it. But after it cranks and cranks with no sign of catching i do pump it several times. Info just in case it might be driver error. Thanks.

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[willcarterdc]

The only insight I can offer is that when I first got my carb back from a professional rebuild, I noticed that my choke also wasn’t fully closing when cold, but instead had about 1/4 inch gap; whereas prior to the rebuild, it had always been fully closed (no gap) when cold. And prior to the rebuild, it would close completely with an affirmative “click” with a slight pull of the throttle lever after the car had started to cool down enough; whereas after the rebuild, it didn’t have that click - it would close, but not completely.

So: I adjusted my choke until I got it back to the prior state - fully closed with no gap when cold, and affirmative click when pulling the throttle lever after it’s cooled down. Starting then became much easier.

I do now wonder, however, why my choke setting would have been changed during the rebuild. It was winter when I sent it to them but mid-spring when I got it back: maybe they were anticipating much warmer weather/a leaner starting mixture being desirable by the time I got it back? Or maybe there’s a simpler explanation: they just don’t look at the choke setting when putting the carb back together after a rebuild, anticipating that that kind of fine tuning will be done on reinstallation. (My carb was rebuilt by Holley. I know they say they “wet flow” bench test their new carbs before shipping them out, but I don’t know whether that’s also true for their rebuilds. My carb didn’t smell at all like gas when I got it back, so I’m guessing not.)

All that said: I don’t know whether “completely closed” or “slight gap” is correct, either objectively or for your carb. You said that your manual doesn’t address this: do you have the manual for the carb itself or just the shop manual? At least in the case of the Holley, there’s a carb-specific manual that provides additional and more detailed info than what’s in the shop manual for my ‘57.

Good luck!

 

[Hernando Muñoz]

Check the adjustment of the needle to calibrate float level at the gasoline accumulator tank. It must be at the lower edge of the threadd of the "bolt window" situated at the latteral wall of the tank.
I beleive you have a problem with your float adjistment.
Also, when you move the throttle linkage (simulating acceleration), does it squirt gas into the venturies? If not, you have a problem to supply gasoline. Start with the needle calibration and then your main pimp operation.

 

[DiIanni]

Welcome to the world of vintage Thunderbirds. You are correct in assuming that you'd get many responses.
In truth, more often than not the problem manifests itself when the engine is hot. To me, yours is a new one.
Before I go deeper, I'd try pumping the pedal 10 times before turning the engine.

 

[PaulB]

The only insight I can offer is that when I first got my carb back from a professional rebuild, I noticed that my choke also wasn’t fully closing when cold, but instead had about 1/4 inch gap; whereas prior to the rebuild, it had always been fully closed (no gap) when cold. And prior to the rebuild, it would close completely with an affirmative “click” with a slight pull of the throttle lever after the car had started to cool down enough; whereas after the rebuild, it didn’t have that click - it would close, but not completely.

So: I adjusted my choke until I got it back to the prior state - fully closed with no gap when cold, and affirmative click when pulling the throttle lever after it’s cooled down. Starting then became much easier.

I do now wonder, however, why my choke setting would have been changed during the rebuild. It was winter when I sent it to them but mid-spring when I got it back: maybe they were anticipating much warmer weather/a leaner starting mixture being desirable by the time I got it back? Or maybe there’s a simpler explanation: they just don’t look at the choke setting when putting the carb back together after a rebuild, anticipating that that kind of fine tuning will be done on reinstallation. (My carb was rebuilt by Holley. I know they say they “wet flow” bench test their new carbs before shipping them out, but I don’t know whether that’s also true for their rebuilds. My carb didn’t smell at all like gas when I got it back, so I’m guessing not.)

All that said: I don’t know whether “completely closed” or “slight gap” is correct, either objectively or for your carb. You said that your manual doesn’t address this: do you have the manual for the carb itself or just the shop manual? At least in the case of the Holley, there’s a carb-specific manual that provides additional and more detailed info than what’s in the shop manual for my ‘57.

Good luck!

Thank you for your quick reply. My carburetor is a Carter and I do not have a manual for it, just the shop manual. But you hit on exactly what i was wondering. It seems to me the choke should be fully closed when the engine is cold. And that is what I'm going to focus on this weekend. At least its a good place to start. Thanks again.

 

[74 Harley]

Yes, your choke should be closed all the way. The other thing to check is to make sure there is fuel in the carburetor.
Before you start the car next time pull the air cleaner off hold the choke open and cycle the throttle while looking into the carburetor. If you're not getting a good shot of fuel then you have more issues than a choke adjustment.

 

[PaulB]

Welcome to the world of vintage Thunderbirds. You are correct in assuming that you'd get many responses.
In truth, more often than not the problem manifests itself when the engine is hot. To me, yours is a new one.
Before I go deeper, I'd try pumping the pedal 10 times before turning the engine.

If it would only be that easy. I hope you're right and I'm going to try and do just that. You are correct though. Once the engine has fired up and ran for a few minutes, then i turn it off, it starts again immediately.

 

[Ward 57]

Thank you for your quick reply. My carburetor is a Carter and I do not have a manual for it, just the shop manual. But you hit on exactly what i was wondering. It seems to me the choke should be fully closed when the engine is cold. And that is what I'm going to focus on this weekend. At least its a good place to start. Thanks again.

Once it does start. Does it hold at high idle until you blip the throttle? A small adjustment of the choke is probably in order. I'm sure on rebuild they set the choke to the indicator on the choke housing to the indent on the cover. Every choke spring is a little different along with the high idle adjustment screw.

 

[jack-in-sac]

I know this is a problem for many old cars and there are probably several posts and dozens of reasons why an engine will crank and crank before it eventually starts. But let me share my situation and perhaps we can narrow it down. I had a professionally rebuilt carburetor installed and prior to that it started okay. The crank was not long, but not quick either. Maybe 10-15 seconds. Now it cranks for over a minute and never starts. I'm sure I probably flooded it. After about 3 or 4 minutes I try it again and maybe after 15 or 20 seconds it tries to catch then eventually does start.
Because the carburetor was the only recent change, I suspect that is where the problem lies. I had it timed too, but I have spark at the plugs and coil so pretty sure the problem is fuel not ignition. I did notice the choke is not fully close when the car is cold and wondered should it be completely closed or open a 1/4 to 3/8 of in an inch like it is now? My manual doesn't really address that. Besides the choke is there any other adjustment on the carb that i should look at. Or could i be looking in the wrong place and its something else. Oh, and when i try to start the car after its been sitting for a week or more, i press the accelerator pedal twice then leave my foot off it. But after it cranks and cranks with no sign of catching i do pump it several times. Info just in case it might be driver error. Thanks.

This may have nothing to do with your problem in starting, but here is my two cents: Yes I do think the choke should probably be adjusted. Additionallly you mention that the engine was timed. How many miles do you have on the engine. An engine with quite a few miles on it may need to be timed by vacuum rather than by the use of a light. As the engine wears things like the timing chain stretch and change the atual timing of the engine.

 

[willcarterdc]

Does it hold at high idle until you blip the throttle? A small adjustment of the choke is probably in order.

Mine does indeed stay at high idle til I tap the gas pedal. What does that indicate?

 

[Ward 57]

Mine does indeed stay at high idle til I tap the gas pedal. What does that indicate?

That it's working correctly. Your issue is fuel delivery after sitting. It shouldn't take that long even with a boiled dry carb. I'd start at the tank connections and look forward while idling for tiny leaks that let the lines drain when sitting. Do you get the squirt in the throttle body when you pump the throttle before starting?

 

[willcarterdc]

That it's working correctly. Your issue is fuel delivery after sitting. It shouldn't take that long even with a boiled dry carb. I'd start at the tank connections and look forward while idling for tiny leaks that let the lines drain when sitting. Do you get the squirt in the throttle body when you pump the throttle before starting?

Thanks! But sorry for any confusion: I raised this question, but I’m not the original poster.

 

[Ward 57]

Thanks! But sorry for any confusion: I raised this question, but I’m not the original poster.

Not an issue. But if you have an ongoing issue you could start a new post or search for something similar.