My 87 was the same as shown, and I've seen an 89 4cyl and it was the same as well.

My astrovan had the same problem, except at any fuel level below 1/4 tank and any state of acceleration.

The only fix I can see is a fuel dam around the pickup with doors that only swing in. I think the FI tanks have one built in, or so I remember from having my tank out and having it tanked to get the old fuel and rust out.

Not responsible for advice not taken...