Resistance is added to spark plug wires and spark plugs to greatly reduce RF radiated from spark plug wire. MSD’s 8.5mm Super Conductor Wire will measure about 50-ohms per foot of wire while the Street Fire brand wires have about 500 ohms per foot. My old wires have much higher resistance: around 9,5 k Ohm (9,500 ohm), that's for the long one. 95 nissan Altima. Video tutorial on how to test a spark plug wires. High Performance: High performance doesn’t always mean a long lifespan, and some types of high performing spark plug wires may need relatively frequent replacement (every 30,000 to 40,000 miles). Over time spark plug wires will wear out, causing various engine operation issues such as hard starting, misfires, rough idling, poor performance, poor fuel economy, and improper combustion burn. Resistance is not the most important detail to be concerned with when choosing spark plug wires. I just wanted to get some numerical values in relation to the spark plug resistance comments. (free air has a RF impedance of 377 ohms). Super Max II spark plug wires have two fiberglass braid layers and an intermediate silicone-EPDM layer for extra insulation, giving them a larger diameter. The more efficient the wire the more spark energy is transferred to the spark plug. Resistance check shows value from 0.15 - 0.34 kOhm (1,500 - 3,400 ohm). Spark ignition is resistive sensitive. To much resistance in the spark plug wires. As far as there being more factors than the resistance, I agree. You can also measure the resistance of each spark plug wire, but like coils, values may vary between wire brands. We also saw a number of cases where high-resistance Champion plugs caused serious internal arc-over damage to Slick magnetos (mostly in Cirrus SR20s). Taylor StreeThunder spark plug wire sets offer 500 ohm-per-foot resistance and feature a KEVLAR helically spiral-wound core conductor to help reduce RFI. Start fresh with a new distributor cap, rotor and spark plug wires. It does this by making an RF impedance mismatch between spark wire (antenna) and free air. Spark plug wires normally last … A resistor spark plug will delay the time when the spark jumps. The thing these spark plugs had in common were that they were all Champion-brand plugs and they all measured very high resistance or even open-circuit when tested with an ohmmeter. Getting too low with resistance is a problem because the wires are then … Most wires should have 650-700 Ohms per Foot if they are in good condition. High resistance in plug wires is generally caused by breaks in the conductor material of the wire and generally when that gap exceeds the gap of the plug then a misfire results. The shortest ignition wire is only 2.85 kohm. that would have shown as a very high resistance reading and not a low one like you found. Hmmm, 5 wrong answers, until this post. Thinking of replacing spark plug wires (hadnt been done by me since getting the car in 2001). Voltage builds in a ramp regardless of how the spark is generated. However you indicated that a "strand of conductor was jutting out" thus the Also be sure you have the correct spark plugs installed. Increasing Resistance : Perhaps the best way to tell if your spark plug wires need to be replaced is to test their resistance. We didn't get into testing ignition coils yet, but that's my next step to see if there's a difference other than the harness plug and the spark plug wire connections. The basic function of a spark plug wire is to conduct spark energy from the ignition source, whether it be a distributor or coil pack, to the spark plugs. The new premium wires from Napa.