by TTait » Thu Oct 28, 2021 2:17 am
It may have to do with the type of fuel filler you are using. Here in the US some states have clean air systems where there is a flexible tube with slight vacuum that meets up with the gas filler neck on the car, and the metal tube runs inside it (California for example) and other states where there is maybe just a rubber flap further back on the fuel filler that deflects any splash if you overfill the car.
The Clean air California style is often problematic with older cars, causing the problem you stated or not wanting to pump unless you manually pull back some on the outer tube without fully inserting the metal fill tip. I've had exactly the problem you describe on some pumps, and not on others, depending on how this system is configured. Also, higher pumping rates make the problem worse. The car simply can't be filled with the fastest flow rates at some stations near my home.
I don't have any blockages in my fill pipe, but it may not allow air to vent back out as the fuel goes in as fast as it did in 75.
Tom
On my third H Body - 1975 Monza 2+2 4.3L Orange/Black (Current State: Running great - needs the AC finished before summer hits hard)
76 Monza 2+2 L4 (1982-1987)
77 Starfire V6 (1987-1987)
82 Delorean - Universal Raffle Car (2005-2013)
81 Delorean 2009 - Present
17 Chevy Bolt 2017- Sold back to GM for almost a full refund
22 Mustang Mach E on order