[s-cars] I'm broke but my car is filthy rich

[Bill Mahoney]

DN,
In case you haven't noticed, these cars are old.  Not just old but old and boosted.  That said, the grin inducing siren song of 80 to 1xx seems too much to walk away from, especially considering how much it may cost to replace these "long in the tooth supercars."
But I digress, and can only add a tidbit that worked to omit a maddening engine " skip" that led my old sister to sell her '92 to D Warren's bro since she needed 100% reliable car.
Anyhoo, apparently after DW's bro tried assorted remedies, they swapped out ecu's and the problem went away... then reinstalled old ecu again and problem remained away.
So, maybe just a disconnecting and reconnecting of the ecu will fix your issue?  Or , not, but at any rate if it works, it's a free fix and won't take long.
Good luck!  Report the fix when you find it.
Bill~off n on~m