Intermittent no spark-misfire on the 5-8 bank
OBD-I car. This was a tough one to find, as there were no codes,and the SD-2 tester revealed no faults. I could see the trigger waveform on my Picoscope, but the signals were noisy and low in amplitude. All of the coil and ECU voltage and resistance tests indicated no problems. Yet, backfires were noted almost immediately after 10-15 seconds of running. Fuel pressure tested within specs. A compression test done and was within the normal ranges. So what's left? Sometimes, pictures do speak a thousands words. Note that this "stuff" is on the component end, not the harness side. During the recent major service, any corroded connectors/torn boots were replaced.
Soon to be happy client...and yet another F355 due in on Monday. Yes, you guessed it. The CEL is on.