| 1992 Vette Misfiring intermittently |
Subject: 1992 Vette Misfiring intermittently by ecorti95 on 2020/4/29 19:31:06 Corvette 1992, 73 K miles, bought it new, the problem is that it started misfiring intermittently a month ago. After driving for a mile or so, briefly misfires and Service Engine Soon, Service ASR, and SYS in speedometer blinks 3 times repeatedly. Also the AC stops cooling. The misfiring gets worse as the engine gets hot. I have been able to get home every time, but seems to be getting progressively worse. I do want to keep this car, it has been fairly reliable. I did have to replace the Opti and water pump at about 40 K miles. The car is stock, except an additional alarm was installed at the dealer when I purchased it. I pulled codes from CCM Diagnostics, jumping Pins A-G in OBD1 connector Module 1: C41, H41 - Loss of ECM Serial Data Link Module 4: No error codes, or sometimes if the car is hot it displays ERR Module 9: H62 - Tach Pulse malfunction H72 - Loss of Data between CCM and EBTCM ECM Diagnostics, jumping Pins A-B in OBD1 connector. Only display blinking code 12, or no reaction if there was a Module 4 Err when pulling CCM codes I have read lots of posts from this and other forums, but I don't see a consensus about the cause of this problem based in the codes and pattern of misfires. Some recommend replacing the ECM, some replacing the CCM, some indicate it is a wiring issue involving the Serial Data Link wires that are shorting, or grounding. Can anyone provide some additional information that can help me troubleshoot and solve this problem? Thanks in advance! |
