Loss of fuel pressure when the Cabriolet get moving

[vuuron]

Ok I need suggestions. I have been working on a 1986 VW cabriolet I bought for my son.
When we took the car down the road to fill it up, on the return trip I would get the car into gear and I would try to accelerate and after a few seconds we would start getting bucked around and the engine would try to stall. I would take the car out of gear and rev the engine a little.(looks good) then try to accelerate again. After about 30 seconds it would buck again. So began the slow trip back home. The car only seemed to get agitated above 2nd gear or while trying to acelerate. Has anyone had a similar issue?

[briano1234]

Is there a loud whine form the rear passenger wheel arch when this is happening? You can hear it from the inside of the car.

I would look at fuel delivery, as in quantity or pressure tests.

If there is a loud whine then you could have a in-tank pump failure that is causing the primary pump to fail.

If you run on less than 1/4 of a tank then it is a possibility that the in-tank pump is gone, and that is causing a restriction on the main pump that squeals until it stops.

A wonky fuel pump relay can also cause this issue.