help please

You just may have a hairline crack on one of your computer modules, and when it heats up, it expands and the connection is rejoined. That is one possibility. If you can when the temp is below 70 and it is causing problems, have someone put a code reader on it and see if all systems are working. Once the engine warms up, the under hood temp shuld be above 70. Does that help?

Its your temp senser by the thermostat

I have a 92 does the same thing, it did it for 2:years now this year it's cooled off and it stopped

Ambient air temp sensor in the air intake housing ,temp sensor by thermostat housing check the two large grounds one on back of rt head the other frnt of engine left side looking at it ,its just below the mount thats bolted to the head also when you change any thing b sure the batt is disconnected and or reset the codes every time you change something .