Thunderbird 1994 8Cyl OHC Misfire Diagnosis: PO306 Injector Grounding Issue

Model: Thunderbird Fault Code: P0300 Posted: 2005-08-10 14:13

I have a 1994 Thunderbird with an 8-cylinder OHV engine. The vehicle is showing a diagnostic code PO306, indicating a misfire on cylinder 6. Upon investigation, I found that the injector for cylinder 6 is not injecting fuel because it's grounded. The power supply to the injector shows a continuous 13V, but when the ECU is unplugged, the grounding stops—replugging and re-grounding restores the signal. All other injectors function properly and show normal signals during testing. When tested individually, all eight injectors operate correctly. However, cylinder 6 fails to fire. Is this a known issue related to wiring or grounding? Or could it be that the only viable solution is replacing the engine control module (ECM)?