I was having a hot start issue with my 91 OCC LO5. I have been fooling around with it for about a year, and finally changed the right part.

The car would start cold without an issue. If I drove about 5 miles to lunch, for instance, and it sat for about a half hour, it would fire, and immediately stall. I could get it to chug, and miss if I played the throttle pedal. After about a minute, it would run fine again.

I replaced a lot of sensors with "known good" spares. I eliminated all but a couple of parts. Finally, I thought it might be the pressure regulator, and rebuilt it...well, that made it worse. So, I finally found the culprit. The last part I swapped out was the IAT, and it has started hot reliably since then.