Need help diagnosing a no spark condition
Thread Starter
Race Director
Joined: Sep 2002
Posts: 17,881
Likes: 25
From: The third orange grove on the left
Need help diagnosing a no spark condition
I drove the car to pick something up at the store and it was running fine. I came out 5 minutes later and the car would crank all day but would not start. I had it towed home and the car does not seem to be generating spark. Fuel pressure is good at the rails. I put in a new coil and ICM with no change to the condition. The opti has less than 10k miles on it so I'm wondering if it could be something else. Any ideas would be greatly appreciated 
Car is a 1995 LT1
Codes:
1. C12
4. H16
4. H77
9. H76
A.
1.0
Car is a 1995 LT1
Codes:
1. C12
4. H16
4. H77
9. H76
A.
1.0
Last edited by Sawbone; Jul 3, 2010 at 11:44 AM.
Race Director
Joined: Dec 2006
Posts: 10,383
Likes: 4
Before I went down the opti replacement road I would want to actually check for spark with a spark test tool. I would also want to pull out a spark plug and see wet gas on it.
The historical code 16 module 4 would be opti low res. But if it is the problem then why isn't it a current code?
The historical code 16 module 4 would be opti low res. But if it is the problem then why isn't it a current code?
Thread Starter
Race Director
Joined: Sep 2002
Posts: 17,881
Likes: 25
From: The third orange grove on the left
Before I went down the opti replacement road I would want to actually check for spark with a spark test tool. I would also want to pull out a spark plug and see wet gas on it.
The historical code 16 module 4 would be opti low res. But if it is the problem then why isn't it a current code?
The historical code 16 module 4 would be opti low res. But if it is the problem then why isn't it a current code?
Race Director
Joined: Dec 2006
Posts: 10,383
Likes: 4
I don't want to cry wolf or make you uneasy but there was a window of time not too long ago when there seemed to be a rash of rotors falling off after xxx miles because the two screws backed out. If you get to the point where the only thing left is the opti you may want to pull yours and look at it before you buy a new one. It may be that the cap and rotor are cheaper than the whole opti. Of course you will secure the screws with red loctite if you do have to replace the opti or the cap and rotor, I'm sure.
Cruising
Joined: Jun 2010
Posts: 12
Likes: 0
From: Tampa Florida
Been there too brother. I would say test all your easy options first but if you did not put in a factory or MSD opti it is most likly the opti. I had the same problem bought an opti from ebay for $300 and even put an MSD cap on it and it still crapped out 4 months later. I put in an MSD and no problem. Hope this helps and good luck bro.
