1965 Dodge Polara w/ 383 Losing Fuel While Driving

[65Polara383]

A few days ago, I finally got my car timed correctly and it runs great. But there is a problem I have not been able to figure out.

After hard acceleration, or accelerating normally up a hill the car will run out of fuel at the carb. It has a new gas tank, sending unit, fuel pump, and all fuel lines have been checked.
When it runs out of gas, I have to pull over on the side of the road and manually add gas to the carb to get it to turn over until the float bowl is refilled. There is also a very strong raw fuel smell under normal acceleration and it gets very strong when the car runs out of gas.
This is definitely not an electrical problem, the car has a Pertronix Ignitor II ignition and matching coil. The coil gets proper voltage and the car normally starts and runs very well.
The tachometer shows the correct RPM and the engine continues turning, it just has no fuel entering it and the fuel bowl is empty by the time I have pulled over to check.

If anyone has any idea how to fix this, please let me know. I want to get back to driving this car as soon as possible.

 

[3175375]

Needle and seat and/or float levels.

 

[65Polara383]

How would I check for this? I am fairly new to working on carburetors.

I had the carb professionally rebuilt by a Mopar mechanic who used to build small-block drag racing motors. I feel like it would have been set up correctly.

 

[65Port]

Are you sure it is not getting flooded out? If the smell of gas is that strong, there has to be gas either leaking or dripping somewhere. Have you noticed black smoke at all when driving?

I want to keep this simple so:

What starting procedure are you using when this happens? Pedal down or no pedal?
When you say fuel lines were "checked", what does that mean specifically?
I would not touch the carb until you know more. You can always run it on an under-the-hood gas can to eliminate the tank and hoses.

 

[65Polara383]

No visible emissions of any color while driving.

Under normal conditions, the car starts without any pedal applied just like a late model car.
Pedal down never produces good results with this car, the only way to start it is with no throttle applied.
Pumping the gas before starting does not help when it has stopped on the side of the road as there is no fuel in the float bowl.

All metal fuel lines were checked for leaks/deformities and flushed out less than a month ago, all rubber lines were replaced.

 

[MoPar~Man]

You say the carb has run out of fuel, that the bowl is empty. Are you disassembling the carb while it's sitting on the engine to know this?

It could be that the tank is not being vented properly. Try unscrewing the tank gas cap (or removing it completely) and drive like that for a while and see if you still have the problem.

 

[65Port]

Typical flood start condition is to press pedal down and keep it there. Maybe try that? Have you also looked to see if the carb is squirting something/anything when you run into this condition?

Other things to check - fuel tank venting, sender problem (if truly running out of fuel).

 

[65Polara383]

The way I am assessing that the carb has run completely out of fuel is that the accelerator pump will not squirt any fuel when this has happened.

The fuel tank and sending unit are less than a month old and should be working fine, I will still try running without the gas cap though.
Would anything with the fuel tank explain the horrible gas smell?

Also, the spark plugs are a perfect tan color with no signs of fouling and the idle screws are as lean as I can set them while still having a smooth idle.

The engine just spins with so signs of starting if I keep the pedal to the floor.

 

[CBODY67]

The fuel tank might be new and all, but are the vent lines hooked up AND the proper type of gas cap installed. Driving without a gas cap is a sure way to empty the tank on the road if the filler neck is behind the license plate! Seems like the orig caps were "Anti-Surge Vented"?

I'll concur that checking the accel pump to gauge the float bowl fuel level is valid, as the accel pump fills from the bottom of the float bowl. Which carb? Are there any drilled fuel passages which are sealed with solder and ball bearings on their outer parts of the carb float bowl?

There are three pieces of rubber hose in the fuel line between the tank and the fuel pump. Were all three pieces replaced with new, quality rubber fuel line? Just curious.

When the engine dies after load, does it just quit like you tuned off the key or does it sputter as if it is running out of gas?

A worn fuel pump push rod might explain the reduced pumping capabilities of the fuel pump in keeping the float bowl full, but not explain the strong fuel smell issue.

IF the carburetor has some drilled passages which end on the front side of the bottom of the float bowl area, it has been noted that ethanol'd gas will compromise the solder seal that is around the peened-in ball bearing to seal that passage. THAT might explain the fuel smell, which needs to be discovered and fixed.

Just some thoughts,
CBODY67

 

[MoPar~Man]

Do you recall if your tank has a vent port? I think it's possible to buy a new tank (Spectrum brand) with 1, 2 or no vent ports. The original tank would have had 1 or 2 vent ports. If you bought one without a vent port, you'll need to do something with the filler cap so that it can vent (allow air to move in and out of the tank). You might be creating a vacuum lock situation.

Other possibilities is that the pickup strainer is plugged or not flowing well, and the same for the filter between the pump and carb. I think some filters are directional so make sure it's hooked up in the right direction.

I've bought a spray can of engine start and spray it into my carb when I've been doing carb work or when I know the engine will be cranking a while to refill the fuel line. The engine can start right away and that saves battery juice and isin't so hard on the starter.

 

[jorkkeri72]

mine did the same when fuel pump pushrod was worn.

 

[65Polara383]

I have a Comp Cams fuel pump pushrod that I will go ahead and install to see if it clears up the issue.

I have checked all of soldered areas of the carb for leaks as that was my first thought as to what would cause the gas smell. Good to know about ethanol eroding them though.
The carb is a Stromberg WWC.

This is the fuel tank I have: Gas Tank 1966 Fury 1965 - 1966 C-Body. I found it recommended in multiple threads on this forum, it connects to the factory fuel vent lines. The vent lines are hooked up correctly.
The gas cap is behind the license plate, I had the same thought about that dumping the fuel. It is non-vented as far as I can tell. The gas cap is the same type all parts sites say is correct and was on the car when I purchased it.

All rubber fuel line was replaced with new, quality fuel line.

When the car dies, it usually sputters a lot but will keep going with a small amount of throttle until the fuel level goes up again. Sometimes though, usually on steep hills, it will completely die.

Also, does anyone here know what size allen key is needed to remove the fuel pump pushrod plug?

 

[CBODY67]

Thanks for the verifications and information on the carburetor.

CBODY67

 

[MoPar~Man]

The photos on the Vans Auto site show 2 shots of the front of the tank, one shows 2 vent ports, the other shows no vent ports, so that's confusing.

The P/N CHCTNK02A comes up on a lot of sites as being for '65 - '66 C-body, I wouldn't have thought there was a change for '67 - anyone know if this is true?

 

[65Polara383]

The tank I have has 2 vents, 1967 received a smaller gas tank in a slightly different shape. You can make them fit, but its not worth it when you can buy the correct tank.

The photos are of the different ends of the tank, it fills from behind the license plate so the filler neck goes in a similar position to the sending unit on the other side.

 

[65Polara383]

Just found the issue, my fuel pump pushrod was worn. Once replaced the carb started getting the proper amount of fuel, which it then leaked all over the intake manifold.

Time for a new carb I guess.

Thanks so much to everyone who helped me out with this!

 

[Ol'Blue]

Glad to hear you found the problem.

If it helps: About 20 years ago my 68 Plymouth Fury 383 Carb needed replacement. I found an Edelbrock Thunder series that has worked well (1805 model I think). I also purchased the calibration kit to tune it. As I recall, it worked find out of the box and I did slight changes with the kit.