5.0L (1979-1995) MustangTechnical discussions on 5.0 Liter Mustangs within. This does not include the 5.0 from the 2011 Mustang GT. That information is in the 2005-1011 section.
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I have a 91 5.0 that is unmodified from stock save for the headers and exhaust. It was running fine and then one morning it was idling very rough and dying. No changes were made to the vehicle to my knowledge.
First thing I did was run fuel injector cleaner through it just hoping it may be a dirty injector. No dice.
KOEO codes are 15 and 33. No KOER codes.
What should I check next to track this problem down?
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From what I've read the code 15 can either be an ECU failure or improper voltage supplied to the ECU. The voltage from pin 1 to ground should be 12 volts, mine reads 11.86. Does anyone know if this is within acceptable range?
I also took a look at the ECU and did not see any blown resistors or bulging capacitors. Is it typical for an ECU to be bad without showing any signs of physical failure?
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