I have a 64 LeMans. This car has the vent return line from the gas tank as well as the fuel supply line from the tank. My problem is that if the car sits for a couple of days the fuel drains out of the system and the care won't start without priming it. I have changed the fuel pump twice and the problem persists. Can someone help me out here please

I don't have an answer. But I have a 62 grand prix with three twos that does the same thing?????????????????????

On 6/21/2020 at 3:20 PM, Chuck Randall said:

I have a 64 LeMans. This car has the vent return line from the gas tank as well as the fuel supply line from the tank. My problem is that if the car sits for a couple of days the fuel drains out of the system and the care won't start without priming it. I have changed the fuel pump twice and the problem persists. Can someone help me out here please

Sorry I know this is a little belated! My guess is you more than likely have a carb the leaks fuel either due to a bad gasket or needle valve, jets or throttle shaft. Basically when you shut the car off the fuel drains out of the bowl into the intake. This allows the float to open over and over till the pressure is relieved enough to stop flowing into the fuel bowl. Then the bowl empties and the carb is dry. So when you try to start the car it’s Trying to start a new carb for the first time. 
if you drive the car, get it hot, shut it off for 5, 10 or 15 minutes is it hard to start?

23 minutes ago, Last Indian said:

Sorry I know this is a little belated! My guess is you more than likely have a carb the leaks fuel either due to a bad gasket or needle valve, jets or throttle shaft. Basically when you shut the car off the fuel drains out of the bowl into the intake. This allows the float to open over and over till the pressure is relieved enough to stop flowing into the fuel bowl. Then the bowl empties and the carb is dry. So when you try to start the car it’s Trying to start a new carb for the first time. 
if you drive the car, get it hot, shut it off for 5, 10 or 15 minutes is it hard to start?

Agree with Last Indian.  When the fuel bowl empties, float drops and needle valve opens allowing air to drop the level in the gas line back towards the fuel pump. 

ofbsac.....  You need to start with your middle carb.  Usually that's where you find this prob.  Your outside carbs are only used at full throttle. Check all connections in fuel line for leaks or the tell tale brown stains around them.

Edited June 23, 20205 yr by JUSTA6

Thanks guys for the responses. It sound like you guys nailed it . I will have the card rebuilt and see if we can stop the leak from the carb bowl

Appreciate your input!

 thanks

that is what I thought  

I make sure the two outside carbs are opened often so the gas doesn't get bad.

same in my GTO

10 hours ago, ofbsac said:

 thanks

that is what I thought  

I make sure the two outside carbs are opened often so the gas doesn't get bad.

same in my GTO