88 Plymouth reliant dyes when driving down road what could it be ?

SOURCE: Engine Races

sounds like a faulty idle speed sensor

SOURCE: belt broke that drives the water pump and

You can loosen the alternator that should releive the tension on the belt.
When you tighten it again make sure you can only turn the belt 90 degrees then you know you have the right tension.

SOURCE: Changing the Fuel Filter on a 1988 Plymouth Reliant

MAKE SURE KEY IS OFF USE A BUCKET AND TAKE OFF LINES TO THE FILTER YOU WILL LEAK SOME THEN REVERCE THE SAME WAY BACK BUT MAKE SURE THE ARROW IS POINTED TOWARD THE ENGINE ON THE FILTER

SOURCE: hi i have a 88 plymouth reliant and i went to

This is called the thermostat houseing and once the bolts are out of it and the rad hose is off then simply put the new one on.

SOURCE: 89 reliant plymouth car stall out

You're right; It sounds like fuel delivery, but start with the simplest suspects first.
Change the fuel filter(s) first, and if this doesn't get it, go for the fuel pump.