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Hey all,
I posted this a couple of times, but I've been reading messages about engines on our cars that run bad, miss, etc. I have a 97 3.8 Firebird, and finally licked this problem after replacing just about everything else.
My car had an intermittent miss. Even after I used MSD 8.5mm Superconductor wires, the car still missed. Our engines run hot, and being located under the dash doesn't help things. The #6 wire/boot seems to get the brunt of the heat. On my MSDs, after 30,000 miles, the wires were fine but the #6 boot was cracked, and most likely shorting out the #6 plug. This must have happened much sooner. Ever wonder why GM was replacing wires under the special extended warranty? They new the wires crapped out early due to the heat.
Here's my fix: I took off the boots for wires #1, 3, 4, and 6 for my MSD universal set. You can buy new 90 degree ends for these. I then used Napa spark plug wire heat sheathing and slipped it over the wires, up to the point where it met the wire loom (from the plug end to the wire loom). This protects the wires from the heat, as the wires run under the manifolds. I did this for all but wires 2 and 5, as these were far enough away. You may want to mark the wires at the looms first with a felt pen.
I also installed Design Engineering's Protect-A-Boot over all 6 spark plug boots. These boot covers cover the entire 90 degree boot and protect them from the heat and possible cracking/arching, especially #6. The stock GM metal boot shields sometimes will cause the boot to arch/short out on them. If you use these Protect-A-Boot covers, you won't need these.
So far, this cured my problem. The steps above totally protect the wires/boots from the heat of the exhaust manifolds, and will prevent missing problems caused by this.
Oh, by the way, use top quality wires. After 30,000 miles, I checked each of my 6 msd wires, and all were within specs, like new.
So if you have this problem, you may want to try this. I hope this helps anyone avoid paying for unnecessary parts caused by this common problem.
I posted this a couple of times, but I've been reading messages about engines on our cars that run bad, miss, etc. I have a 97 3.8 Firebird, and finally licked this problem after replacing just about everything else.
My car had an intermittent miss. Even after I used MSD 8.5mm Superconductor wires, the car still missed. Our engines run hot, and being located under the dash doesn't help things. The #6 wire/boot seems to get the brunt of the heat. On my MSDs, after 30,000 miles, the wires were fine but the #6 boot was cracked, and most likely shorting out the #6 plug. This must have happened much sooner. Ever wonder why GM was replacing wires under the special extended warranty? They new the wires crapped out early due to the heat.
Here's my fix: I took off the boots for wires #1, 3, 4, and 6 for my MSD universal set. You can buy new 90 degree ends for these. I then used Napa spark plug wire heat sheathing and slipped it over the wires, up to the point where it met the wire loom (from the plug end to the wire loom). This protects the wires from the heat, as the wires run under the manifolds. I did this for all but wires 2 and 5, as these were far enough away. You may want to mark the wires at the looms first with a felt pen.
I also installed Design Engineering's Protect-A-Boot over all 6 spark plug boots. These boot covers cover the entire 90 degree boot and protect them from the heat and possible cracking/arching, especially #6. The stock GM metal boot shields sometimes will cause the boot to arch/short out on them. If you use these Protect-A-Boot covers, you won't need these.
So far, this cured my problem. The steps above totally protect the wires/boots from the heat of the exhaust manifolds, and will prevent missing problems caused by this.
Oh, by the way, use top quality wires. After 30,000 miles, I checked each of my 6 msd wires, and all were within specs, like new.
So if you have this problem, you may want to try this. I hope this helps anyone avoid paying for unnecessary parts caused by this common problem.
