'86 5ktq stumbles/bucks then dies...

[Arryn Milne]

Hi all,

Any ideas?  Here's the long version:

I was cruising along the interstate at 80mph or so, about 20 mins into a 
trip, then the car starts bucking/stumbling/hesitating (more of a buck) for 
a mile or two, then died completely.  No start.  Sat for about 15-20 mins, 
then it started and ran normally for about 8 miles, then the same sequence 
as before.  Waited an hour, but this time it wouldn't start at all.  Towed 
it home.

Tried:
Fuel pump not noisy.
Tried new FP relay.
Checked fuses.
Checked ignition by using a spare plug and grounding it.  Big fat spark.
Pulled fuel pump out just to look at screen on the bottom (clean), and 
inspect the tank (looks ok).
Checked ECU ground.

New items on car (in last year):
Injectors
Fuel Filter
Idle Stabilization Valve
Distributor cap & rotor
Spark plugs
Spark plug wires
Timing belt, water pump, etc.

New items the year before:
Throttle switch
Decel shutoff valve
IC-TB hose

After pulling the pump, etc, I used a spare injector (yep, still have the 
old set) to see if there was enough fuel pressure to crack the injector 
open.  There is.  So there seems to be ignition, and there seems to be fuel 
(but that's after sitting for days, being worked on, etc).