I don't use a cable, but here is one from Motorsports Auto... http://www.thezstore.com/page/TZS/PROD/classic13/10-1862
No sure on the zx, but on the s30 there is a smaller metal arm on the firewall that turns when you press the gas pedal. I extended that with a small piece of metal, then hooked it up using a throttle connection rod.
TH