Accelerator cables have a hard life on the automatic. The cable attaches to
the kickdown lever on the tranny and has a lot of pulling to do for both the
kickdown and throttle.  At 160k miles my son's 87 finally broke Sunday. He
was returning from a 300 mile trip and it broke 3 miles from me and my home
shop, His first "ride of shame" since purchase 5 years ago. He was able to
coast off the very busy road to a safe parking place. These vans have good
"carma".  The cable is $35 with shipping from our vendors, and takes about
an hour to replace the first time, mostly due to tight space around the
tranny.

The cable wears at the point where it exits a protective tube and rubs on
the metal end fitting there.  Lube your new cable there  (under the flimsy
protective bellows)  before installing and be sure to check that you have
full throttle when the pedal is  floored and that the tranny kicks down when
floored while driving. I recommend doing this job every 100k now.  Be
careful not to damage the bellows when you  install it.

Stuart