btr85vette

I recently bought a 1985 Corvette that has been sitting for about 4 years. It had some pack rat damage to the wiring. Anyhow, I have the car running really strong, but have a problem. Originally, the SES light would come on with a 43 as soon as I started the car. I checked the Knock sensor connector, and it was damaged, so I replaced it. Now, the SES does not come on when I start the car. If I romp on it, I get like a 1 or 2 second ping from the motor, then the SES light comes on. After the first ping, it does'nt ping again until the car is shut off and restarted. Then I get a code 43 and a 54 (fuel pump low voltage.) The weird thing is that I can eliminate the 54 depending on how I move the KS connector; it seems to react to interference around the connector. After the SES comes on, I don't notice a dropoff in performance like the timing is being retarded.

Has anyone seen this scenario before? I don't want to start the slow death of randomly replacing parts.

josephf31

43 an EST fault?

3 pedals

You need to get a factory shop manual or another book that has the trouble codes with a diagnostic flow chart. This will guide you in checking the wiring (in case a rat chewed a wire in two) and the ESC module. I would start with code 43 first and once that is gone see if code 54 goes away. There shouldn't be a link between the two, but you never know. Grounds are critical in our vettes and a bad ground connection can do goofy things.

floridamale

1985-1991: ECM Codes
Code #12: Normal No Codes.
Code #13: Open Oxygen Sensor Circuit.
Code #14: Coolant Sensor Circuit Low.
Code #15: Coolant Sensor Circuit High.
Code #21: Throttle Position Sensor High.
Code #22: Throttle Position Sensor Low.
Code #23: Manifold Air Temperature Circuit High.
Code #24: Vehicle Speed Sensor.
Code #25: Manifold Air Temperature Circuit Low.
Code #32: EGR System Failure.
Code #33: Mass Air Flow Sensor High.
Code #34: Mass Air Flow Sensor Low.
Code #36: Mass Air Flow Sensor Burn-Off Function Fault.
Code #41: Cylinder Select Error.
Code #42: Electronic Spark Timing.
Code #43: Electronic Spark Control.
Code #44: Lean Exhaust indication.
Code #45: Rich Exhaust Indication.
Code #46: Vehicle Anti Theft Fault.
Code #51: Faulty Mem-Cal.
Code #52: Fuel Calpak Missing.
Code #52: (1990-91 Corvette Only): Engine Oil Temperature Sensor Low.
Code #53: System Over Voltage.
Code #54: Fuel Pump Circuit Low Voltage.
Code #55: Defective ECM.
Code #62: Engine Oil Temperature Sensor Circuit High.