When to Replace Spark Plug Wires?

[cannabinoid]

Hey guys,
Recently replaced the starter on my wifes 1997 Accord SE ( 4 CYL, Auto).
It fixed some issues she was having starting the car up for the second or third time in the day. Sometimes having to wait 10-15 minutes and several cranks until it responded, since replacing the starter she has not had that issue.

However I went ahead and purchased Distributor Cap & Ignition Rotor for replacement as well, was told it is a good idea. My question is should I go ahead and replace Spark Plug Wires as well? How long do they Last?
We purchased the vehicle at 149K and now has 190K, my guess is with original wires.

Thanks Everyone

*My apologies, I ment to post this in Mechanical/Maintenance Forum*

 

[AKhan87]

take a multi-meter and test the resistance between the two ends, use OEM specifications to compare.

OEM Honda wires that I tested, 10-18 years old, were all perfectly within OEM specs.

AEM Honda wires new & old that I tested were COMPLETELY out of spec.

Never saw a reason to ever change them, just double check to see if the insulation looks good or not.

All my Toyotas are ignition coils, never seen a single one fail yet, I have over 230k miles on two OEM sets which still function flawlessly.

 

[Merkava_4]

Yes change them out. Use Genuine Honda Parts.

 

[BRZED]

Measure resistance, but also, at night, with the engine running and the hood open, spray water mist with an atomizer over the wires and see if you see any arcing.

 

[holdorf333]

Only time I've replaced wires was because of cracked jacket or broken terminal. Above is a good way to go as well. A guy I work with tested his OEM wires from a '92 Merc SL. Resistance was within spec and way lower than aftermarket wires from Autozone.

 

[berniedd]

Honda says high tension wires should not have more than 25,000 ohms resistance for any one wire.

 

[AKhan87]

Originally Posted By: berniedd
Honda says high tension wires should not have more than 25,000 ohms resistance for any one wire.
I never saw an OEM honda spark plug wire that went past 14k

 

[OneEyeJack]

As I remember I've replaced my spark plug wires on my Honda twice since I purchased it new in 1984. I did it based on the look and feel of the wires because they tested good but started to feel rough and stiff to the touch. I examined them with a magnifying glass. They started to develop very small surface irregularities and very tiny dull spots not easily visible to the unaided eye, on the sides near the exhaust manifold. So you could say I replaced them based on the insulation, not the conductors. When I replaced the wires I also replaced the coil.

 

[ragtoplvr]

IF this was happening then Honda would have to replace them under the emissions warranty. So what was your criteria for replacement.

Rod

 

[SteveSRT8]

We have run factory wires far beyond 2-300 k miles. As long as they are within spec and do not misfire then you are aok to keep them forever IME...

 

[bigt61]

When they start to misfire under load, that's the time to replace them. Climbing a hill in high gear is a good test. Don't replace parts until you need to - especially stuff like plug wires. Even if they go bad, they won't leave you stranded by the side of the road. A fuel pump you know is going bad? - that's a different story.

 

[buck91]

As 01_celica_gt mentioned the proper why is to test resistance. The shop manual should provide a resistance spec in ohms/foot, so measure the resistance of each wire, then measure the length in feet and divide.

Most of the vehicles that I've had that were 15+ years old were at the top end or even out of spec; I don't buy Hondas though.

Also, another consideration is insulation breakdown. If you are getting misfires in wet weather you may be getting voltage loss through the insulation. I don't know of a diagnostic for this other than if you are trying to track down poor fuel mileage, rough idle or misfires.

 

[Brad_C]

Originally Posted By: buck91

Also, another consideration is insulation breakdown. If you are getting misfires in wet weather you may be getting voltage loss through the insulation. I don't know of a diagnostic for this other than if you are trying to track down poor fuel mileage, rough idle or misfires.


Easy diagnostic. Start 'er up at night in the dark and gently spray water (like with a garden sprayer or the one your wife uses while ironing. Little droplets in a mist rather than a heavy spray) over the ignition components. If the insulation is failing you will see corona discharge as it glows a pretty blue.

As you and everyone else has said, plug leads have 2 failure modes. High or increasing resistance and insulation breakdown. Both cause a weak spark contributing to fuel economy issues and eventual misfires.

Measure resistance, and wiggle the lead around while you are doing it looking for significant changes. That'll weed out any dodgy connections or broken conductors as well as looking at the overall end to end condition.

I just measure them end to end and inspect the insulation. If it looks good it's pretty likely it is good. Ignition leads don't wear like caps or rotors, but failing leads will often cause your cap and rotor to wear faster. Ignore all of that for wasted spark or individual coil systems of course

 

[HerrStig]

DO you hear ignition noise on weak AM radio stations? IMHO NGK wire is better than stock.

 

[GMBoy]

Wires are cheap. I don't bother testing them, just replace them at every spark plug change at the recommended intervals.

Keep it simple.

 

[Superflop]

Yup testing is the best i rarely have to change plug wires. I prefer taylor wires their insulation is fantastic.

 

[PandaBear]

There is one time I had wires worn out and crumbled into powder on a neglected and misfired to heck Ford Escort due to way worn out plugs and dirty MAF sensors.

Another time I had leaking valve cover gasket that swelled the wire boot and I replaced them.

Another time I accidentally crushed a wire when I installed valve cover gasket, so obviously I have to replace it.

Honda once replace a set of wires plus oil change and plugs at 150k as an emission warranty extension service.

That's all the incidents I can think of.

 

[buck91]

Originally Posted By: GMBoy
Wires are cheap. I don't bother testing them, just replace them at every spark plug change at the recommended intervals.

Keep it simple.


Maybe "service grade" replacements on a 4 banger. Any quality wireset for my V8 runs a decent amount. Certainly more than I pay for the plugs!

 

[hpb]

Originally Posted By: SteveSRT8
We have run factory wires far beyond 2-300 k miles. As long as they are within spec and do not misfire then you are aok to keep them forever IME...


^ Correct answer. Save your money.

 

[sleddriver]

Welcome to BITOG!

I just discovered mine are 11 yrs. old! I've also experienced a couple of CEL's relating to same cylinder misfires. Wires live a rather hard life under the hood. I would have replaced mine before now if I'd been keeping track better.

Re: Measuring. While you can take a simple DC resistance meas. with a DVM, I suspect it won't give you the whole story compared to using 20kV, full acceleration, 3000 rpm. High voltage, under load, tends to see resistances quite a bit different than 1.5VDC, with no load.

My indy told me to check using a spray bottle of soapy water in a dark garage with the engine running. Looking forward to doing this.

If you suspect they've never been changed, since 1997, I'd change them, particularly since you also bought a cap + rotor.