Topic: Problem: Miss / Cause: Burnt plug wires!
in Forum: C3 Engines
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C3VR Founder
Eagleville, PA - USA
Joined: 11/1/2001
Posts: 18384
Vette(s): Used to own a 1979 Corvette now owned by JB79
My engine was having a major missing problem recently...
I pulled the plugs and wires. Plugs were pretty beat, not fouled, just very used. I don't think the plugs were the problem.
The wires, however, were another story! 2 of the wires were burnt and cracked in the middle, because they were pretty much laying on the exhaust manifold. 2 other wires were burnt and cracked at the boot that goes on the plug, I suppose because they sit right next to the exhaust manifold. The first 2 make sense... they shouldn't be sitting on the manifold. The second 2 I don't understand. They are always as close to the manifold as they were when I looked at them. Why would they burn?
Anyway, I replaced the four burnt/cracked wires with new ones and replaced all the plugs and she runs like a champ again!
|UPDATED|8/17/2003 6:44:12 PM|/UPDATED|
I pulled the plugs and wires. Plugs were pretty beat, not fouled, just very used. I don't think the plugs were the problem.
The wires, however, were another story! 2 of the wires were burnt and cracked in the middle, because they were pretty much laying on the exhaust manifold. 2 other wires were burnt and cracked at the boot that goes on the plug, I suppose because they sit right next to the exhaust manifold. The first 2 make sense... they shouldn't be sitting on the manifold. The second 2 I don't understand. They are always as close to the manifold as they were when I looked at them. Why would they burn?
Anyway, I replaced the four burnt/cracked wires with new ones and replaced all the plugs and she runs like a champ again!
|UPDATED|8/17/2003 6:44:12 PM|/UPDATED|
-Adam Wartell
NCM Lifetime Member #1222
Founder: C3 Vette Registry
C4 Vette Registry, C6 Vette Registry
My first Vette, now owned by JB79:

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Hi Adam
How old were the plug wires?
When your car was built you were lucky to get 3 years
out of a set!
Todays silicone wires are much better and should
last a long time!
Happy motering!
Steve
How old were the plug wires?
When your car was built you were lucky to get 3 years
out of a set!
Todays silicone wires are much better and should
last a long time!
Happy motering!
Steve


C3VR Founder
Eagleville, PA - USA
Joined: 11/1/2001
Posts: 18384
Vette(s): Used to own a 1979 Corvette now owned by JB79
Steve said: Hi Adam How old were the plug wires?... |
I'd say they were about 1 year old.
-Adam Wartell
NCM Lifetime Member #1222
Founder: C3 Vette Registry
C4 Vette Registry, C6 Vette Registry
My first Vette, now owned by JB79:

Is there a heat shield between the plugs and manifold? If that is missing then you should replace them. Make sure the wires are turned so they are as far from the manifold as possible. Some times that gets overlooked. Good luck.
Brian - NCM Lifetime Member
73 coupe L48, Flat-top pistons, Performer RPM Heads, Crane Cam and roller rockers, Holley 650 vac sec. Performer intake,
3.55 gear BTO 200-4R trans,
Leather seats, Seatbelt Plus 3point seatbelts, Pioneer CD player
Magnaflow Exhuast System
Dewitt radiator and dual electric fans
Borgeson Steering box

The most important thing I was told by a friend mechanic when I replaced the plug wires on Ian (78 Vette)was to keep the wires clear of the manifold. that is the main problem you had Adam. There were 2 wires burnt that weren't on it but very close to it. The car has after market chrome manifold covers , so it also has chrome wire holders. I fit the wires properly in the holders with rubber grommets and kept them far out from the manifold even when running them to the distributer cap. i was very surprised from annother post by you that you said you ran them through the manifold pipes. that seems too close to me. Couldn't they be routed out around them. We had to have the battery cable replaced when Colleen first got the car because it ran along the bottom of the engine and was literally fried.
it was causing a bad starting and shorting out problem. Now with a new longer, heavy duty wire the mechanic was able to keep it away from the bottom of the engine. That is my biggest surprise with the Vettes. They are so hot and prone to problems related to heat.
|UPDATED|8/26/2003 12:14:27 PM|/UPDATED|
it was causing a bad starting and shorting out problem. Now with a new longer, heavy duty wire the mechanic was able to keep it away from the bottom of the engine. That is my biggest surprise with the Vettes. They are so hot and prone to problems related to heat.

|UPDATED|8/26/2003 12:14:27 PM|/UPDATED|
Former Member
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DOWNINGTOWN, PA - USA
Joined: 11/24/2001
Posts: 962
Vette(s): 1969 Monza Red Black Conv / Black Vinal hardtop
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2004 Yellow convertible with black top and black interior
Guess I have to ask a dumb question. You said you replaced all the plugs and the four burnt wires. Why did you replace all the plugs and only 4 of the wires?
in Forum: C3 Engines
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