Dies/cuts out
 

Only hot humid days the van will cut out for a few seconds at highway speeds after driving 2-3 hours. In town it will die and restart. Then it does this it will ack up many times In a row.

Can't say with certainty being fuel injection but sounds like the age old problem of "vapor lock" as would occur in carbureted cars. Fuel can reach a condition on hot days when it will get so hot air locks develop. Would shut motors down, stall and sputter. Cool cans packed with ice were used for racing with fuel line coiled inside. Carter made an AFB carb with phenolic body which helped with hot fuel, but......

Perhaps cheap gas with too much ethanol or other could cause a similiar problem in fuel injected vehicles, never heard of this as happening, always a first I guess?