Okay, my EFI light has a habit of coming every few days if the temp gauge goes to about 75% - when the EFI light illuminates, the temp drops back down to normal. Cooling system isn't leaky, and coolant is clean. Engine doesn't seem to be overly hot. Could this be caused by a bad sensor or bad connection? - This is a hotwire system with an early ecu - as far as I know, this ecu doesn't 'do' fault codes like the later models. Any ideas which sensor might be bad or any other suggestions? Can an airlock in the cooling system show up as symtoms like this? I did pull out and swap the temp sensor with another one (not known to be definitely good) without draining the coolant, however problem was there before this time.
TIA from BC Canada
Lewie