To change or not to change, simple tune up ???..

[Moparman01]

Doing a basic tune up on a 340 I have, new plugs, fuel filter, air cleaner yadda yadda yadda. Anyway, a buddy of mine said make sure you put in new plug wires as well, it's a must. Ok, but why? Well it has been 8 years since I've done any tune up to this motor, when I did I put in brand new Accel wires on it. The car has only been driven about 5000 miles since then, do plug wires really go bad in 8 years/5000 miles (plus regular start ups over the winter months). I just don't like being wasteful with either good parts or money. What's everyone's take? How about cap/rotor (i will visually inspect them however). The 340 is pretty much stock with and edelbrock intake and carb, Mopar electronic ignition. Thanks!

[justcruisin]

Inspect them for any damage/burning. Check that fittings in the boots are clean and tight on the cap and plugs. Do an ohms test - normal TVRS cable could be as high as 8000ohms per ft. Cables like MSD super conductor or fire core are like 50 ohms per ft. Establish which leads you have and look for a reading that is out of line with the rest, if all looks good I wouldn't have any issues with re-using them If you don't have any engine miss and the cap and rotor appear to look OK I would re-use them also. Don't see the point in replacing stuff if it is not needed, in saying that I do carry spares like coil and complete distributor in the trunk.

[mopar0166]

I normally do a tune about this time of the year - oil, oil filters, air filter, cap/rotor(MSD), trans service, check rear oil, lubricate u joints, grease front end, spark plugs and inspect wires.  I did have to change mine out more frequently with the old set of headers because they would be exposed to a lot of heat. but I normally will change my wires maybe every three years, and then keep the ones I take off as spares. 

This can take some time, but its better then something failing during the summer or fall. 

[c00nhunterjoe]

I replace the wires every 2 years with a good quality set. You are talking about spending 100 dollars every other year on a good set. Pinching pennies in my opinion.

[alfaitalia]

Id only be changing a poor quality set every 2 years!....not a good quality set. Good sets should last 60-100,000 miles according to the manufacturers websites and that's from the folks selling them so you can bet they last longer. Magnecor Race Wires recon they should outlast the engine!! So IMO every two years is throwing money away.....but its your cash. Sure, check then for burns, damaged insulation and resistance once in a while and replace if ness....but just changing them routinely seems a bit unnecessary. IMO...of course!! 

[c00nhunterjoe]

There are also people that go 30,000 miles on engine oil because a lab report said its ok to do it....

Or go 20 years on tires because the still have tread.

[alfaitalia]

Well i will leave it there then....with a well thought through, sensible and logical argument like that I must wrong!

[c00nhunterjoe]

Lol, ok, how about this then; in my experiences with hot ignitions, after 2-3 yrs the car will begin to lose et in the 1/4 mile. Is it going to cause your street car to break down- no. But it does make a difference. And when you have 3 out of 4 posts on this site concerning starting or idle problems, the ignition system is not a place to pinch pennies on.

[firefighter3931]

As Joe mentioned above ; Ignition is not an area you want to cheap out on....yet most do. 

Many leave power/performance/drivability on the table with weak ignition and poorly adjusted timing curves. 

The easiest way to evaluate your ignition wires is to use your multimeter and run a resistance test. If you're seeing more than 250 ohms/ft the wires are suspect. 



Ron

[Moparman01]

This has become a fairly interesting topic! I guess I'll go thru them and check the resistance and go from there (tho I have no idea how to properly use a ohm meter). Like some have said, I don't like throwing away money or parts that don't have to be replaced, I was just curious if plug wires really do degrade much over time or more over distance. My guess would be mileage is worse than overal age of the wires.