Plug wires & missfire
Thread Starter
Pro
Joined: Jun 2007
Posts: 713
Likes: 9
From: Saratoga Springs Ut
Plug wires & missfire
I'm having a problem with a random missfire, and I was thinking that my headers might be heating up the plug wires or just one wire enough to cause a missfire. I never had the problem until I changed over from the stock wires to the MSD wires which don't have a heat sheild on them. The VCM wll not set a MIL so I can't seem to find out what the cause is.
I did notice yesterday that when I was sitting at a light for a while that it started to missfire after I left the light, and it got me to thinking that after sitting at the light for awhile I built up enough heat to case a plug wire to fail.
The missfire is very random. Happens mostly at low RPM (1500-2500) or after I drive it hard. Or on a long steady RPM of about 1500 RPM, but not always.
I did notice yesterday that when I was sitting at a light for a while that it started to missfire after I left the light, and it got me to thinking that after sitting at the light for awhile I built up enough heat to case a plug wire to fail.
The missfire is very random. Happens mostly at low RPM (1500-2500) or after I drive it hard. Or on a long steady RPM of about 1500 RPM, but not always.
Last edited by TheDEfan; Feb 12, 2012 at 11:45 AM.
Instructor
Joined: Nov 2011
Posts: 137
Likes: 8
From: Dallas Tx
Le Mans Master
Joined: Nov 2005
Posts: 5,403
Likes: 31
From: Allentown PA & Elk Twp NJ HPDE Addict
I found the heat shields to be the problem for me after a header install. On some of them they were leaning against the header tube, eventually forcing the plug wire to work its way loose from vibration. I removed the shield on 3 of the wires due to lack of clearance. No problems since and no melted wires.
Thread Starter
Pro
Joined: Jun 2007
Posts: 713
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From: Saratoga Springs Ut
Humm, so should I buy some heat socks for my current wires or get the GMPP wires? Do the GMPP wires come with sheilds? I thew away my old wires and sheilds
Last edited by TheDEfan; Feb 12, 2012 at 11:48 AM.
Drifting
Joined: Jan 2008
Posts: 1,722
Likes: 138
From: Florida
St. Jude Donor '09
I'm having a problem with a random missfire, and I was thinking that my headers might be heating up the plug wires or just one wire enough to cause a missfire. I never had the problem until I changed over from the stock wires to the MSD wires which don't have a heat sheild on them. .
Last edited by ipuig; Feb 12, 2012 at 11:59 AM.
Thread Starter
Pro
Joined: Jun 2007
Posts: 713
Likes: 9
From: Saratoga Springs Ut
Oh no, not another superior quality MSD wire failure, say it isn't so! Check for carbon build-up from arcing on the spark plug's ceramic insulator surface. Once the boot is heat damaged, the seal in between the boot and the ceramic insulator is compromised allowing electricity to bleed through causing a misfire.
http://www.ebay.com/itm/LS1-LS2-LS3-...item4cf9699104
Le Mans Master
Joined: Jun 2008
Posts: 5,284
Likes: 235
From: Rockledge FL
once again GMPP from GMpartshouse.com
half the price of MSD or those ebay nameless knock offs posted.
fits with the oem heatshield even with headers. positively clicks onto the plugs and coils.
half the price of MSD or those ebay nameless knock offs posted.
fits with the oem heatshield even with headers. positively clicks onto the plugs and coils.
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Drifting
Joined: Jan 2008
Posts: 1,722
Likes: 138
From: Florida
St. Jude Donor '09
So I should s**t can the MSD's Are these any good?
http://www.ebay.com/itm/LS1-LS2-LS3-...item4cf9699104
http://www.ebay.com/itm/LS1-LS2-LS3-...item4cf9699104
I klnow nothing of the wires you asked about. The GMPP wires are more than adequate and last a very long time.
Thread Starter
Pro
Joined: Jun 2007
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From: Saratoga Springs Ut
Le Mans Master
Joined: Aug 2005
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From: CA.
St. Jude Donor '13-'14-'15
Not a fan of the LS MSD wires---The problems seem to be in the boots
On the coil boots--- the inside diameter of the boot is too small--make sure you hear them "snap" when you install them-- A trick we learned was to slide a thin tie wrap ( zip tie) into the boot and then put it on the coil--then after you hear it snap--pull the zip tie out---They say the when installing the boots the air has no where to escape beacaue the boots are so small inside and seal too well to the coil--- the trapped air pressure will make the boots pop off-- the zip tie trick eliminates all the trapped air pressure
On the coil boots--- the inside diameter of the boot is too small--make sure you hear them "snap" when you install them-- A trick we learned was to slide a thin tie wrap ( zip tie) into the boot and then put it on the coil--then after you hear it snap--pull the zip tie out---They say the when installing the boots the air has no where to escape beacaue the boots are so small inside and seal too well to the coil--- the trapped air pressure will make the boots pop off-- the zip tie trick eliminates all the trapped air pressure
