Throttle position sensor going bad? (Or connections to it or some other sensor are dirty which could intermittently give the ECU bad data causing havoc.)
On older cars, check all grounds are clean and tight (transmission, body, thermostat housing, valve cover).
Also, make sure battery terminals are clean and tight.
Failing main ground cable (negative battery terminal clamp, body ground, transmission ground)?
take care,
ChrisS
Last edited by ChrisS; 05-01-2019 at 06:13 PM.
Reason: Fixed mistake