I hesitated in posting since not sure if same problem:
Before replacing the distributor (I actually considered this as well), try removing the dust. I cleaned the dust in the optical sensor area back in 2007, no problem since.
FYI:
Similar problem several years ago…depending on the outside temperature…could go 30-60 miles without any problem…then it would hesitate, buck and stall. I had to allow the van to sit (i.e. cooling off, rest?) for a period of time before it was drivable again.
Tested many areas and replaced a few questionable parts. During that period, replaced the fuel pump (check valve problem). No luck, improved performance with problem still existing.
It has been several years here how I removed the dust:
I removed the distributor cap, rotor and cover over the camshaft sensor area. Using a portable vacuum, I carefully removed as much dust as possible (~ an inch away). Next I taped a drinking straw to the opening end of the extension attachment of vacuum and again carefully vacuum (much closer). Using air (I used a portable air compressor) blow the area for the remaining dust (I also used a rag to help from migrating the dust further into the distributor). I finish up with the straw vacuum setup, especially concentrating around the optical sensor. Reassembled distributor.
Hope this helps
Wide Track