just a question. when I fill up my car after driving her for a while, if the engine is hot, I start the car, drive her for awhile and then she quits. now it doesnt happen each time, just when its hot, and funny enough only after filling up the engine. at no other time does the engine just quit. and after it does quit, well then it takes about 20 minutes or an act of God to get her started back up.

I'm running an original I6 170. the gas lines run up the block on the drivers side away from the exhaust manifold, but i'm sure its still hot. is this just vapor lock or something else. and if it is vapor lock, whats some ways to prevent this? thanks in advance..

 

I’m pretty sure its not vapor lock or it would do it more then just when you put gas in it.

You could try running supreme or retarding your timing that may help prevent hot start problems.

Gun

 

If I understand your post correctly, you are saying that while driving for around 20 minutes after filling up, the engine will just die. Is this correct?

If it acts fuel starved;
Could be a few things, first thing that comes to mind is that there is something in the the tank next to the pick up that gets stirred up when you fill the tank. A good boil out at a radiator shop and a fresh filter sock on the pick up tube would cure that issue.
Secondly, your cap could be making such a good seal that the pump (as it is getting old) can not overcome the seal to keep drawing fuel with a full tank. When the fuel first goes in it expands due to heat once it stabilizes and there is no room in the tank for air to expand the fuel pump starves. If this is the case. Simply removing the cap and cranking the engine for 10 seconds should refill the carb. one depression of the pedal and it should start back up. I'd suggest cleaning and rebuilding the fuel pump if you can still get the kit.

If it acts flooded;
Cap is sealing so well that as fuel expands in the tank with heat, it raises the pressure above what the float needle can handle. Again simply opening the cap slowly (so you don't get splashed with gas) should tell you. If that is the case, after opening the cap, place the accelerator to the floor and crank the engine for no more than 10 seconds at a time until it starts.
If this is the case, I'd try a different fuel cap.

I'm sure there are more scenarios, but that gives you something to start with anyways. I agree that vapor lock is a more constant issue, then just when filling up, although a week fuel pump could cause vapor lock like symptoms, with a full tank.

Good luck,

 

thanks for all the information. I'll definately give your suggestions a try.

 

I would bet that if it only does it after you fill up, that you have some crud in the tank and it gets stirred up when you fill it up. Next time you are close to empty, take out the sending unit and check to see if the sock has rust particles all over it. Vapor lock will happen every time she gets hot, then you shut it off and try to start it again. Gas boils in the carb and vaporizes. Pop the hood when you turn it off and listen to the carb. If it is vapor locking, you will hear the gas boiling. The cure for that would be a phenolic spacer under the carb.