temp not correct like too cold the engine will run rich because the ECU via the coolant temp sensor will increase the injector pulse time as if engine in warm up mode. This happened to me. So check coolant temp sensor and its connector and if you have an infra red temp gun check the operating temp at the thermostat housing. My 92 NA runs at 180F warmed up. The best way to ckeck the thermostat is to pull it and do a pot on the stove top check with a thermometer. To go to that trouble might as well as replace. If you do the replace use an OEM thermostat (better made than after market) and check it out on the stove in a pot of water and thermometer.
In my case the thermostat was open too far at the 170 F start to open point and the valve modulation was faulty. Thus engine ran cooler with idle issues and greater fuel consumption.
