Coil Ground Wire Missing
Thread Starter
Instructor
Joined: Apr 2017
Posts: 156
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From: Cleveland Ohio
Coil Ground Wire Missing
I'm trying to diagnose why I have crank/no start problem with my '96 LT1. I had the engine out to do leaking gaskets, plugs, wires, etc. It was running fine when removed aside from the oil leaks. Now that it's back in it will crank but not start/run. It does this odd thing where I can crank it and when I stop turning the key the engine will still rotate for a couple seconds but not actually run, if that makes sense.
The tach needle moves so I *think* that means the opti is at least sending a signal. In looking at the grounds in the service manual there is one listed next to the coil/ICM. It appears to ground to the block. However, I do not see any ground terminals or extra wires coming out of the wiring harness. This has been a loooooong project to say the least so I'm not 100% on my recall of taking everything apart to pull the engine. I labeled the entire harness. Is this some kind of FSM error? Can anyone confirm a '96 LT1 has a ground wire next to the coil/ICM? It's number 6 in this pic from the manual.
The tach needle moves so I *think* that means the opti is at least sending a signal. In looking at the grounds in the service manual there is one listed next to the coil/ICM. It appears to ground to the block. However, I do not see any ground terminals or extra wires coming out of the wiring harness. This has been a loooooong project to say the least so I'm not 100% on my recall of taking everything apart to pull the engine. I labeled the entire harness. Is this some kind of FSM error? Can anyone confirm a '96 LT1 has a ground wire next to the coil/ICM? It's number 6 in this pic from the manual.
Thread Starter
Instructor
Joined: Apr 2017
Posts: 156
Likes: 36
From: Cleveland Ohio
I haven't had time to start running fuel pressure, check injectors, or start probing the ICM, coil, etc. This was just a visual place for me to start and hope I missed something obvious. The car ran fine before I pulled the engine so my first thought was I missed a ground hooking everything back up. Also worried the new cap/rotor has something wrong. I've seen posts where people got a rotor that wasn't set up right and not making contact w the cap.
Team Owner
Joined: Sep 2003
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That seems odd! The FSM mentions the tach filter in cluster 8A-82-0 etc. It of course references 8A-20 but in '96 with OBD2 that 'cell' of the 8A was moved to the 6 (engine section). I've no interest but you pointed out the diagram and the question.
Thread Starter
Instructor
Joined: Apr 2017
Posts: 156
Likes: 36
From: Cleveland Ohio
I'm thinking the FSM wasn't updated to reflect '96s not having a tach filter. Thus, that ground wire I can't find on my car is just that, not there. I'm hoping someone else w a '96 could verify they don't have a ground in that location next to the coil.
