I might be barking up the wrong tree but for me not uncommon. Seems like when my gauge reads around 1/4 tank I start getting the bucking syndrome. Is it possible the tank is lower than what the gauge reads and the pump is sucking air? I can drive through it with acceleration but when I back off it starts the hucka buck..Does any of this make sense?

Is the "low fuel" light lit?
Supposedly the sender can stick, but the light's always correct.
Mike

I've had the same experence. Believe the light, the gauge can be off.

Well no light for low fuel level. but then the bulb might be burned out. I'll check the bulb manana.

Make yourself a dip stick from a piece of wood dowel. Periodically dip your tank and compare those readings to your fuel gauge as you go thru a tank of gas. Can't do this in most cars but it's easy in a 914.

constriction in fuel delivery somewhere? Mind you that should get worse under accelleration not better.

Yep, just like the early bugs. Its great having to stop periodically on long trips to dip a wooden stick into the tank to see how much fuel you have

My 74 2L FI engine did the same thing at low fuel levels. Just slight bucking here and there. I attributed this to air bubbles from the movement of fuel in the fuel tank pickup.

Since fuel is going into the tank from the return fuel line and fuel is being sucked into the fuel line right next to the returned fuel, it would seem that at low fuel levels that the returning fuel could be causing bubbles which are sucked back into the fuel pickup.

Conversely, if the fuel level is low and you do a quick turn and uncover the fuel intake in the tank, air bubbles again are introduced into the fuel system and are injected into the cylinders instead of gas.

My solution to this in my 914 and 911 is to use the 1/2 tank level as the refuel level.

Only asking, but are the return line and supply line reversed?

my old 57 bus just had a "reserve" lever for when it ran out... and this was o.e.

mike