96 LT1 firing problem
Thread Starter
1st Gear
Joined: Apr 2012
Posts: 1
Likes: 0
96 LT1 firing problem
I have a 96 vette with LT1 that stopped firing. I've replaced the distributor and the module, and I still cannot get fire at the plugs. I have spark at the coil and through the coil wire, but nothing at the plug wires. The car was running OK and stopped at the store and then just turning over no start! I did park at the edge of the house about a month before and after a hard rain the car would not start, so I put a fan under the hood blowing on the distributor and after a couple of hours it started. This is why I believed it was the distributor, which was not easy to replace. After no start then I replaced the module too: nothing! Then I started checking the components by the chilton's repair manual. But I have not figured it out, please help!
Race Director
Joined: Dec 2006
Posts: 10,383
Likes: 4
Read the DTCs and post them here please.
post about how to read codes on 94-96 cars: http://forums.corvetteforum.com/c4-t...n-96-cars.html
post about how to read codes on 94-96 cars: http://forums.corvetteforum.com/c4-t...n-96-cars.html
Safety Car
Joined: Sep 2010
Posts: 3,752
Likes: 190
From: Indiana PA
If you have spark at the coil and and thru the coil wire but NOT at the plugs. You have a plug wire problem or distributor cap/rotor issue.
The Opti Part of the Distributor must be working, if it was not, then you most likely would have NO spark anywhere.
How are you testing for spark at the plugs?
Take that Chilton's/Haynes manual and use it for back up toilet paper.
You need a Factory Service Manual to work on C4's. You won't find a better information resource anywhere unless you have Gordon Killebrew on speed dial.
The Opti Part of the Distributor must be working, if it was not, then you most likely would have NO spark anywhere.
How are you testing for spark at the plugs?
Take that Chilton's/Haynes manual and use it for back up toilet paper.
You need a Factory Service Manual to work on C4's. You won't find a better information resource anywhere unless you have Gordon Killebrew on speed dial.
Intermediate
Joined: Sep 2006
Posts: 38
Likes: 1
Are you using an inline spark tester (light) to verify spark or just looking for an arc from the plug wire end?
I have seen 2 cases with LT1/4s that had the same no start after opti replacement where it ultimately turned out that the existing spark plug gap was too large to fire across. Once the plugs where replaced (and gaped) the engines fired right up. In the one case the opti was replaced as a precautionary after the water pump failed so the engine ran on the old opti but not on the new one.
If you used a Dynaspark opti they call for a .035" to .045" plug gap as opposed to the factory gap which I believe is .050". If the plugs have been in there a while the gap can grow quite large.
I have seen 2 cases with LT1/4s that had the same no start after opti replacement where it ultimately turned out that the existing spark plug gap was too large to fire across. Once the plugs where replaced (and gaped) the engines fired right up. In the one case the opti was replaced as a precautionary after the water pump failed so the engine ran on the old opti but not on the new one.
If you used a Dynaspark opti they call for a .035" to .045" plug gap as opposed to the factory gap which I believe is .050". If the plugs have been in there a while the gap can grow quite large.
Instructor
Joined: Dec 2006
Posts: 137
Likes: 0
Are you using an inline spark tester (light) to verify spark or just looking for an arc from the plug wire end?
I have seen 2 cases with LT1/4s that had the same no start after opti replacement where it ultimately turned out that the existing spark plug gap was too large to fire across. Once the plugs where replaced (and gaped) the engines fired right up. In the one case the opti was replaced as a precautionary after the water pump failed so the engine ran on the old opti but not on the new one.
If you used a Dynaspark opti they call for a .035" to .045" plug gap as opposed to the factory gap which I believe is .050". If the plugs have been in there a while the gap can grow quite large.
I have seen 2 cases with LT1/4s that had the same no start after opti replacement where it ultimately turned out that the existing spark plug gap was too large to fire across. Once the plugs where replaced (and gaped) the engines fired right up. In the one case the opti was replaced as a precautionary after the water pump failed so the engine ran on the old opti but not on the new one.
If you used a Dynaspark opti they call for a .035" to .045" plug gap as opposed to the factory gap which I believe is .050". If the plugs have been in there a while the gap can grow quite large.
Check your old cap for carbon tracking due to worn out/increase gap plugs. Replace the plug wires also while your at it.
Best regards,
