1988 EA82 SPFI, a/c converted by a shop from R12 to R134a, typical central Florida summer temps in the low 90's and humid. Everything works dandy, decent amount of cooling (for a conversion). Problem I'm having is that over the course of a drive, particularly stop and go, the car nears the overheating mark on the gauge, hitting say between 2/3 of the sweep to the tick for the start of "red". NOT running the a/c, I can pretty much romp the crap out of all day and never get warmer than the half mark, just enough to kick the fans on for a few and cool it back down.
The cooling system was flushed the backyard method with flush from Autozone, a/c condenser was power washed free of debris while off the vehicle, expansion valve and receiver/drier replaced with new, aftermarket dual electric fans installed and functioning correctly via OEM setup. I see no evidence of a HG leak anywhere in the coolant, engine oil, unusual smoke from exhaust, etc.
Any thoughts, before I throw more money at it? Car is equipped with what appears to be the original single-row all-metal radiator; I can get a new twin-row all-metal radiator but hate spending the money if it isn't going to fix the issue.
Special question for Jeszek: did you have heat issues with yours before switching to the twin-row radiator?