Where this fits
By this point in a first start-up you've had the injectors disabled, confirmed the ignition is firing and calibrated the ignition timing. Now you turn the fuel back on. If you unplugged the injectors earlier, plug them back in first, then re-enable them in ESP (the reverse of disabling injectors).
Getting it started and idling
- Crank it. If it doesn't fire, change the fuel in small steps between attempts, adding or removing until it catches. Don't keep cranking a flooded engine.
- Keep it alive. Once it runs, adjust the fuel trim and the fuel map cells around idle RPM and load until it idles smoothly. A wideband makes this far quicker than working by ear.
- Know what "normal" looks like. A typical engine idles around 1000 rpm with about -60 to -80 kPa of vacuum (roughly 18 to 24 inHg). A big cam will pull less vacuum, so treat that as a guide, not a target.
- Recheck timing. With the engine running, put a timing light on it and confirm it's firing at the angle set in the Lock Timing parameter. Trigger offsets that looked right while cranking can shift once the engine is running.
Watch the basics while it warms up
Keep an eye on oil pressure, coolant temperature and leaks for the first few minutes. A fresh install is the time to catch a loose fitting.
With a steady idle and correct timing, the setup phase is done and you can start tuning. Our guides to idle fuel and mapping an engine are the natural next steps.
