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Spark Plug Wire Replacement


tmpafford

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Just finished replacing the wires on my 97 STS.

Front wires were no problem except for the plastic wire loom. What a pain.

Rear wires were a real pain! Three clips, wire loom sleave, clip to hold the sleave and everything tucked under the coil pack.

For those of you who have done this, how many of you put all the clips, looms and electrical tape back into place?

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It was good that you did what you did, you lessened the chances that you will have problems. I would do the same as you. As a matter of fact I spent an hour last week cleaning, rerouting and putting the loom on my wires after they did my fuel rail and after I cleaned my EGR .

I recently responded to a post where the fellow was inquiring about a code he was getting and one of the primary reasons the code comes up is because of EMF from misrouted ignition wires that interfered with the injector firing. As we also know the HVAC blower circuit board is suseptible to damage from EMF. You did good! B)

Its ALWAYS harder to do the job right.... :P I usually end up with a back ache after plugs or wires!

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For those of you who have done this, how many of you put all the clips, looms and electrical tape back into place?

I did mine a few thousand miles ago. I put most of the clips back on, but didn't loom them or use any electrical tape. I think that was mostly for mass assembly purposes. I didn't see the benefit of looming them up, since they were retained well by the clips.

Jason(2001 STS, White Diamond)

"When you turn your car on...does it return the favor?"

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I did mine a few thousand miles ago. I put most of the clips back on, but didn't loom them or use any electrical tape. I think that was mostly for mass assembly purposes. I didn't see the benefit of looming them up, since they were retained well by the clips.

I do not see much benefits of looming the sparkplugs either. High voltage would rather leak to the ground over the surface of a cheap plastic loom than through an air gap. Perhaps they loom the wires just to keep them separate? The most appropriate material to isolate a high voltage source from the ground is the Teflon.

The saddest thing in life is wasted talent

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Also did mine a couple weeks ago, I also changed plugs while I was at it. I found it very easy to do by pulling off coil packs along with all the wires. Mine had plastic protectors around the wire looms that had some electrical tape on them. I made sure everthing was just like it was, only because on mine I have to worry about blower motor circuit board. And what a difference let me tell you, I was having trouble with cold starts but would run fine after start. She fires up instantly once again. AC DELCO for all parts.

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Jason and Adallak, I realize that I am probably the belt and suspenders guy of the group, but...if the wire loom was unnecessary it is unlikely that GM would include it to begin with. How many times have you moved a wire to see a burn mark where the wire touches another wire or where it touches metal. Given all of the EMF sensitive items under our hoods I feel its best to go stock..

Because an ignition spark always takes the easiest path to ground, a failing spark plug (or with a wide eroded gap) can cause the spark traveling in a wire to find it easier to induce itself into an adjacent wire (cross-fire) or to ground on the engine. On any engine, it’s never a good idea to allow spark plug wires to touch each other, or rest against metal parts of the engine. Jason you are correct there are a lot of nice clips but they are near the fuel rail, injector wires, etc. Just my $0.02.. Mike

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Jason and Adallak, I realize that I am probably the dynasaur of the group, but...if the wire loom was unnecessary it is unlikely that GM would include it to begin with. How many times have you moved a wire to see a burn mark where the wire touches another wire or where it touches metal. Given all of the EMF sensitive items under our hoods I feel its best to go stock..

Because an ignition spark always takes the easiest path to ground, a failing spark plug (or with a wide eroded gap) can cause the spark traveling in a wire to find it easier to induce itself into an adjacent wire (cross-fire) or to ground on the engine. On any engine, it’s never a good idea to allow spark plug wires to touch each other, or rest against metal parts of the engine. Jason you are correct there are a lot of nice clips but they are near the fuel rail, injector wires, etc. Just my $0.02.. Mike

Mike,

What I am saying is that the plastic loom does not provide with electrical isolation for kV pulsed voltage as say, electrical tape does in case of 120V AC. If there is a way to create an air gap between the high voltage wire and lower potential surface by other means than a plastic loom it would work much better. Nevertheless, in some cases a plastic loom may be the only way to provide such separation. If it is possible to root the wire so that there is 3 mm air gap between the wire and say, engine block it is much better than having 3 mm lastic loom wall between them. Hope, this example makes things more explicit.

The saddest thing in life is wasted talent

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While I understand what you are saying, then I must question why GM is wasting so much money using it. If it is useless, why would GM use it, sounds like waste to me, I think I better sell my GM stock.... :lol:

Why did Cadillac put loom on my wires when they did my fuel rail not to mention a few others here. I don't know, maybe the wire loom keeps dirt, oils, radiant heat and moisture off the ignition wires which could accelerate rubber insulation breakdown and drying out of the rubber..who knows. Personally I like the way it looks. As I matter of fact, I just ordered this, I like that its high-temp (its green) I have been looking for high-temp for a long time: http://www.jcwhitney.com/autoparts/Product...-ZX/appId-22966

I will continue being Mr. Safety and replicate what the factory did when I can, thanks... :lol:

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While I understand what you are saying, then I must question why GM is wasting so much money using it. If it is useless, why would GM use it, sounds like waste to me, I think I better sell my GM stock.... 

Why did Cadillac put loom on my wires when they did my fuel rail not to mention a few others here. I don't know, maybe its to keep the dirt, oils and moisture off the ignition wires which could accelerate insulation breakdown and drying out of the rubber..who knows. I will continue being Mr. Safety and replicate what the factory did when I can, thanks... 

If Cadillac put loom probably there was no other way to keep the wires separate.

And that's exactly what I said in both my posts if you read them carefully.

What I am also trying to do is explaining that one should not treat a plastic loom just like one treats electrical tape we use in 120 V AC applications. High voltage pulses are different animals.

The saddest thing in life is wasted talent

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If what you are saying it true, then I should have burn marks on my loom at some point on the ignition wires, I will keep an eye out for that. I have to think that the loom provides an increased increment of insulation as it provides more gap than if it were not there, over the length of all the wires I would think this would translate into a positive benefit. Now that may not make sense from an electrical engineering stand point, but in my mind I think that the increased gap helps as I believe that sometimes given the right circumstance say with morning dampness, having direct contact with metal is especially not optimal. To me the loom provides an additional layer of airspace, not to mention that the wire is not tight to the loom. Not to mention protection from moisture.

Besides the benefits I mentioned above, I also think the loom provides protection against chaffing.. Normally I can be convinced, but in this instance I see to many positive benefits for the loom. But most importantly I like the way it looks! :lol:

Even if Guru if said it was useless, I would still use it! :lol::lol::lol:

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I just changed my wires tonight....And yep.....i did wrap them the way they were and I did use all the clips and looms....I figured that if it was good when it was born, I'll keep babying it....It wasn't as bad as I expected getting to the back...Hardest thing for me seemed to be getting the rear coil pack screws back in....I used the dum dum loaded into the socket instead of cramping the fingers and hoping I wouldn't loose one....

Russ

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I just changed my wires tonight....And yep.....i did wrap them the way they were and I did use all the clips and looms....I figured that if it was good when it was born, I'll keep babying it....It wasn't as bad as I expected getting to the back...Hardest thing for me seemed to be getting the rear coil pack screws back in....I used the dum dum loaded into the socket instead of cramping the fingers and hoping I wouldn't loose one....

Russ

I had same problem, even lost my 10mm socket. It fell back along engine cannot locate.

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While I understand what you are saying, then I must question why GM is wasting so much money using it. If it is useless, why would GM use it, sounds like waste to me, I think I better sell my GM stock.... :lol:

I didn't re-loom my rear wires for the reasons Adallak mentioned. I think Cadillac originally loomed the rear wires as a means to facilitate easy assembly, possibly among other things. I'm sure the spark plug wire "assembly" is pre-assembled, meaning the wires are pre-wrapped and pre-clipped when it comes time to install them. When they're installed, I bet they're just draped over the engine and clipped onto the plugs. That's all speculation obviously, but that's what I figure. Obviously, this only applies to the mid-1990s and later Northstars where the front bank spark plug wires route over the intake manifold, rather than all over the water pump area.

My rear wires have plenty of air gaps between them and the block. In addition to the OE clips and brackets, I also used some generic wire separator clips that I had laying around, to reduce the possibility of cross-fire.

I did use the individual looming on the front wires, but only where they crossed the new fuel rail. I think they figured that the metal rail has more of a tendency to absorb ambient heat, and they didn't want one section of rubber insulation laying on a hot metal line all the time. I tend to agree with what they prescribe there, and I loomed the front wires were they cross the new fuel rail.

I'll have to snap a picture.

Jason(2001 STS, White Diamond)

"When you turn your car on...does it return the favor?"

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Did the wire change on Thursday afternoon and went round trip to Little Rock from Houston over the weekend. Engine felt like it ran smoother and my milage went from 22.5 mpg last weekend to 23.6 mpg for the round trip. This was with the cruise control set at 80 most of the way.

Did a WOT before the change and got a little cloud of crud. Did a WOT after and got a big cloud. Did a WOT a third time after the trip and got nothing. Mt theory is that I had one or two cylinders that were not getting a good spark and was not burning the crud and gas very well.

Well worth the price for the new set of wires.

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