Thread: tune/spark plug wires

What numbers is he talking about?

Originally Posted by backinblackgtp

i recently had my gtp tuned, and the guy at the shop told me i need new spark plug wires, saying something about the numbers he read on the wires are too high and should be around 100-300. is this true? in addition he told me until that happens dont beat on the car, but at about half throttle boosting about 5 pounds the car seems to like jerk/bog is this the belt slipping? or something else?

Sounds like you have a misfire possibly due to a bad plug wire not an incorrect plug wire type. How long have you had these wires?

The shop guy was probably talking about the wire resistance. As spark plug wires age they tend to become more resistive. The stock wires I took off my GP measured between about 2000-5000 ohms. At that point they had 45k miles on them and functioning perfectly, just for a reference. That being said, new wire resistances vary a lot. Depending on the wire manufacturer you’re look at a range of about 50 to 10,000 ohms per foot. So really the only easy way to know if a wire is out of spec or not, is to compare it to the other wires on the car.

My wires were 650 ohms at most (number 6 wire) when I put them on.

NGK wires.

Edit: checked it just now, 634 ohms for my number 6 wire.

When i checked them all before i put them on the front bank was around 200-300 and the rear bank around 500-600.

That was probably mostly the timing.