Direct fire (coil per cylinder)
Wire by cylinder number, not by firing order. Ignition output 1 goes to cylinder 1's coil, output 2 to cylinder 2, and so on. The ECU already knows the firing order from your setup and fires the outputs in the right sequence. If you pre-sort the wires into firing order as well, you've shuffled it twice and the engine won't run.
Wasted spark
Wasted spark is the opposite. The outputs fire in plain numerical order, IGN 1, then IGN 2, then IGN 3, whatever the engine's firing order, and each coil fires a pair of cylinders that reach TDC together. So you wire each output to the pair that matches its place in the firing sequence.
Take a six-cylinder with a 1-5-3-6-2-4 firing order. The companion pairs are 1 and 6, 5 and 2, and 3 and 4, so:
| Output | Cylinders |
|---|---|
| IGN 1 | 1 and 6 |
| IGN 2 | 5 and 2 |
| IGN 3 | 3 and 4 |
Distributor ignition
A single distributor always uses IGN 1. With twin distributors the outputs are IGN 1 and IGN 2, and IGN 1 usually fires first.
Confirm the ignition type and firing order in the software, check the wiring against the rules above, and verify base timing with a light. Our ignition and ignition modules notes cover the rest, and fueling for piston engines covers injector order.
