1962 Thunderbird. Hard to start after warm

I have my 1962 convertible running and on the road for the summer. It starts right up when I take it out after a night in the garage. Runs well and had a new carburetor a year ago. Fuel pump newer as well. But if i drive for 20-30 minutes or so and it is all warmed up. After a 15-20 minute stop, it is tough to start. It turns over and over, i then pump and finally floor the peddle and then it come to a roar. Hope there is a simple idea for what to do. Thanks
 
Most likely vapor lock. The fuel is vaporizing in the fuel lines. Trace them and make sure they aren't running too close to any part of the exhaust system. You also might want to wrap some insulation around them in the engine compartment. you might check on the status of the carburetor spacer. and make sure the fuel bowl on the carburetor isn't boiling dry from a hot intake manifold.
 

64ZCODE

Well-Known Member
I wonder if your fuel pump is up to snuff. Might be a good idea to do a pump test and check fuel pressure. I chased an intermittent no start problem for a month on my '64 and it turned out to be a dodgy fuel pump.
 
I have my 1962 convertible running and on the road for the summer. It starts right up when I take it out after a night in the garage. Runs well and had a new carburetor a year ago. Fuel pump newer as well. But if i drive for 20-30 minutes or so and it is all warmed up. After a 15-20 minute stop, it is tough to start. It turns over and over, i then pump and finally floor the peddle and then it come to a roar. Hope there is a simple idea for what to do. Thanks
Hi Rob, A couple of questions and some ideas. What engine is in it? 390 with A Ford 4 bbl carb? What fuel is in it? Assuming Your battery is strong and it is cranking fine when hot, Make sure a good fuel is in it...such as Shell V power Nitro or Exxon/Mobil supreme Premium. Second, Next time you are out and running it and after it is warmed up, shut it off...remove the air cleaner and verify the choke is wide open. When you say you have to put it to the floor and hold it there to get it started, that’s a sign it’s flooded or the choke is not opening. How many times dId you pump the gas pedal when hot starting it, before having to hold the pedal to the floor to start it? Finally if those issues are not the problem I would check the float levels in the carb you replaced. It could have a high float level and it is flooding the engine. Do you small gas when it starts and does black smoke come out the tail pipe when it finally fires up? good luck.
 
I have my 1962 convertible running and on the road for the summer. It starts right up when I take it out after a night in the garage. Runs well and had a new carburetor a year ago. Fuel pump newer as well. But if i drive for 20-30 minutes or so and it is all warmed up. After a 15-20 minute stop, it is tough to start. It turns over and over, i then pump and finally floor the peddle and then it come to a roar. Hope there is a simple idea for what to do. Thanks
Youre going to want to make sure the idle/air mixture screws are dialed in. x2 on sounding like its getting flooded. Try insulating or moving fuel lines away from the block to help rule out vapor lock.
 
Hi Rob, A couple of questions and some ideas. What engine is in it? 390 with A Ford 4 bbl carb? What fuel is in it? Assuming Your battery is strong and it is cranking fine when hot, Make sure a good fuel is in it...such as Shell V power Nitro or Exxon/Mobil supreme Premium. Second, Next time you are out and running it and after it is warmed up, shut it off...remove the air cleaner and verify the choke is wide open. When you say you have to put it to the floor and hold it there to get it started, that’s a sign it’s flooded or the choke is not opening. How many times dId you pump the gas pedal when hot starting it, before having to hold the pedal to the floor to start it? Finally if those issues are not the problem I would check the float levels in the carb you replaced. It could have a high float level and it is flooding the engine. Do you small gas when it starts and does black smoke come out the tail pipe when it finally fires up? good luck.
Thanks Dennis
Yes it is a 390 with 4bbl. I have filled it with Ethanol free gas last couple of times. 90 octane. Not sure if that makes any difference.
I will do the check on the choke. I runs pretty hot but never boils over. I am going to check 2 things. One is the ratio of antifreeze (i think it is way more then 50%) and two, to change the radiator cap from 18 lb to the recommended 13 lb.
When i try to start it when hot, i first turn it over with no pumping. (when cold that is the way it starts) When it won't go, i pump twice to the floor while turning over, then finally hold pedal to floor. Then it starts with a pretty big puff of black smoke and a smell of gas. . Thanks for the advice.
 
Thanks Dennis
Yes it is a 390 with 4bbl. I have filled it with Ethanol free gas last couple of times. 90 octane. Not sure if that makes any difference.
I will do the check on the choke. I runs pretty hot but never boils over. I am going to check 2 things. One is the ratio of antifreeze (i think it is way more then 50%) and two, to change the radiator cap from 18 lb to the recommended 13 lb.
When i try to start it when hot, i first turn it over with no pumping. (when cold that is the way it starts) When it won't go, i pump twice to the floor while turning over, then finally hold pedal to floor. Then it starts with a pretty big puff of black smoke and a smell of gas. . Thanks for the advice.
You’re welcome Rob. Thanks for the reply. Based on your info, I am wondering if you have a fuel filter and if it was replaced recently? The 90 octane, ethanol free fuel is a bit low For your engine. The 390 likes the high octane gasoline’s. I’d suggest you try the Shell or Exxon/Mobil. If you are concerned about the ethanol, my recommendation is to do what I do and use Stabil 360 at each fill up. It eliminates the moisture in the gas left by the ethanol and extends the life of the gas if you store the car over the winter. I’ve been using it for years in my 1967 Mustang GT 390. Other considerations include checking the timing and the condition of the ignition wires, plugs, points and condenser. Finally, depending on your budget and how hands on you like to be, you might consider alternatives to the current carb. If memory serves me your engine came with a Ford Autolite 4bbl. See attached pic. Not a great carb. There are lots of alternatives like Edelbrock and Holley. I use a Holley on my Mustang. But I would first make sure my ignition system and fuel filter check out. Good luck.
 

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You’re welcome Rob. Thanks for the reply. Based on your info, I am wondering if you have a fuel filter and if it was replaced recently? The 90 octane, ethanol free fuel is a bit low For your engine. The 390 likes the high octane gasoline’s. I’d suggest you try the Shell or Exxon/Mobil. If you are concerned about the ethanol, my recommendation is to do what I do and use Stabil 360 at each fill up. It eliminates the moisture in the gas left by the ethanol and extends the life of the gas if you store the car over the winter. I’ve been using it for years in my 1967 Mustang GT 390. Other considerations include checking the timing and the condition of the ignition wires, plugs, points and condenser. Finally, depending on your budget and how hands on you like to be, you might consider alternatives to the current carb. If memory serves me your engine came with a Ford Autolite 4bbl. See attached pic. Not a great carb. There are lots of alternatives like Edelbrock and Holley. I use a Holley on my Mustang. But I would first make sure my ignition system and fuel filter check out. Good luck.
That is great info. I will try some of the things and let you know how I do.
 
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