But before I do this, is my fuel pressure normal (36 PSI at WOT in driveway) or does this look more like ignition/electrical? I'm completely puzzled as to why it starts fine and idles smooth and revs good in the driveway, yet if I shut it down it might stall, then start back and run 'normal' again. This morning when it started I drove it down the street and the low rpm stumble was still there.

 

I just got done pulling off the opti - it's toast . The cap has green corrosion on almost all the terminals, and in the center, plus some of the plastic inside is worn away. New Delphi complete opti plus new GM waterpump going in next weekend. Say your prayers for me!!

 

The problems are now solved. With the new delphi opti, the car no longer stumbles/hesitates, and the intermittent start was being caused by a weak starter.

Thank you to all who gave advice and suggestions. Special thanks to Don and Fred for your expert feedback and instructions

 

Glad you found the problem.