I hear you. OBD-I is a tough nut to crack.
My situation isn’t much different – everything is new, even the ECU was tweaked. The engine has always performed well under load but I’ve had chronic idle issues for years.
Last summer I had hard time passing smog test, and recently, I’ve been experiencing more running problems. I guess whatever it is, it is getting worse:
Nobody knows (or nobody cares) I suppose.
If I have any confidence that the shop near DC that has a working PDU can pinpoint the problem, I’d drive down there and paid them the $150 fee, but VK’s experience with it has been underwhelming and I am hesitant (plus, given the loss of power, I am afraid I might end up on the side of the road calling for a tow-truck)
Good luck,
Steve