How do you know if your car needs Spark Plug Wires?

Question

I was told when I got my car mainteneced I needed spark plug wires and I called other shops and they said my car does not have ignition wires. I have a 1999 Toyota Corolla is there an online directory to where I could find this info or can someone find out for me whether or not my car needs these?

I think you guys are misunderstanding my question. The guy at the shop told me I needed some new ones and but I called another shop and they said they do not make spark plug wires for my car

Answer 1

rough idling.

the car doesn't seem to have power, the get up and go.

Answer 2

That car should NEVER need "ignition wires". Other shops are right. It has individual coils on top of each spark plug. they are triggered by a low voltage wiring harness. Each coil feeds the high voltage spark directly into the plug. unless this wiring harness is damaged in some way it should never need to be replaced.
We have actually come full circle - that is the way the Ford Model T used to fire the plugs back in 1910 or thereabouts. in the 20's or 30's someone - Delco - Delco Remy invented the "distributor" using one central coil - ignition points - rotor - cap and high voltage wires to distribute the 30-40 kV spark. We are now back to the "old way".

Answer 3

Almost all spark plug wires these days are "supression" or "resistor" type wires. This is so you don't get popping noises through your radio.

Unfortunately, supression wires aren't made from metal, they have a conductive substrate that gets old, hard, brittle . . . in short it becomes non-conductive over time.

If you think about it, you only NEED the one center "coil" wire to be of the suppression type.

So . . .

Get solid core copper non-suppression or non-resistor wires for all the spark plugs, and get one suppression type wire for the coil wire.

If you do this, you'll only need to replace the coil wire when the wires become suspect for needing replacement. You can carry one with you as a diagnostic tool.

I've done this for years. Of course I've driven a '66 Chevy for 21 years too. Most people simply replace their car when faced with repairs.

It never ceases to amaze me that someone will confront a $2,000 problem on a $1,900 car and get talked into a $25,000 solution by way of a replacement car. I just don't get the math.
.

Answer 4

Wires can sometimes been seen shorting out, a spark jumping from one wire to the next, that is a good indication you need to change them. Look at them at night with the engine running slow, better on a humid or damp night as that exacerbates the problem making it more obvious to the naked eye.

Usually such shorting will also leave marks on the wires themselves.

Is the car mis-firing? Hesitating? bucking? all signs of possible mis-firing

Any search engine, type in your cars make and model and year, follow the 'net' after that.

Answer 5

Does your car have a petrol engine? All petrol cars have leads going from the distributor to the spark plugs. Also a lead from the ignition coil to the distributor.

Check them for frayed or damaged insulation, or damage to the terminals.

Replace any damaged leads. You can get these from any car accessory shop.

Answer 6

Depending on which engine you have, the 1800 cc 1ZZ-FE family of engines has no spark plug wires, it has four coil packs, one for each spark plug.

Answer 7

at night, open the hood with the engine running. if you can see blue things going through your wires, you need new ones. just do it...it's hard to explain but you'll see what i mean if you do it tonight.