Trouble diagnosing problem
You may have a problem with the venting, or with the pickup tube in the tank. There are several issues
A 73 car has the so called "evaporative emissions controls" Go to MyMopar and download the 73 factory service manual and read the fuel sections, and the emissions sections. THE TANK VENT which is part of the "carbon canister" in the enigne bay is a 1/4" tube from the tank to the engine bay. This MUST be in place and connected and OPEN in the engine bay (or properly connected to what belonged there from factory
Factory caps ARE NOT VENTED. They are what is called "pressure vacuum" which let air in or air out if pressure builds
Be SURE you have the right cap. Caps were different nearly every year from 70 onwards
Here is a famous photo someone posted on here showing the differences
The pickup tube might be damaged, the filter sock plugged, or it might be bent/ broken somehow so that it's only picking up from the top area of the tank
You will have to drain the tank and pull the sender to find out
You may have a problem with the venting, or with the pickup tube in the tank. There are several issues
A 73 car has the so called "evaporative emissions controls" Go to MyMopar and download the 73 factory service manual and read the fuel sections, and the emissions sections. THE TANK VENT which is part of the "carbon canister" in the enigne bay is a 1/4" tube from the tank to the engine bay. This MUST be in place and connected and OPEN in the engine bay (or properly connected to what belonged there from factory
Factory caps ARE NOT VENTED. They are what is called "pressure vacuum" which let air in or air out if pressure builds
Be SURE you have the right cap. Caps were different nearly every year from 70 onwards
Here is a famous photo someone posted on here showing the differences
The pickup tube might be damaged, the filter sock plugged, or it might be bent/ broken somehow so that it's only picking up from the top area of the tank
You will have to drain the tank and pull the sender to find out
