Help. Have a problem hope someone has an idea. I have a 1990 with 45k miles on it. When I start the car all is fine but after about 5 minutes it states to run really bad. Black smoke, will not idle. I get error codes 43 (Electronic Sparta Control) and 53 (System Over Voltage). Thought a bad alternator killed the module but, if I wait 5 minutes the car starts and runs fine again. I reset the codes, disconnected the alternator and have the same problem with the same error codes. Therefore I think the over voltage error is a false reading :confused . How can you have an over voltage error if the car is running off the battery (11.8 v). I don't want to start swapping parts hap-hazardly. Any words of wisdom would be greatly appreciated.