Where cranking fuel fits in
A start on a Nexus happens in stages. The prime pulse wets the ports first. Then, for as long as engine speed stays below the Max Cranking RPM, the Fuel Cranking table delivers extra fuel to help the engine catch. Once it's running above that RPM, the normal fuel table and post-start corrections take over.
The table's units follow your Tuning Method, so it may not show the same units as another car you've tuned. That's expected.
How we tune it
- Get the prime right first. Cranking fuel is for the gap between the prime and a running engine.
- Tune it cold and hot. A cold engine needs much more fuel to start than a hot one, so make changes at the temperature you're testing.
- Read the symptoms. Long cranking that eventually catches often means too little fuel. A start that coughs, smells rich or fouls plugs usually means too much.
- Change one thing at a time and let the engine return to the same temperature before the next try.
Also check your cranking ignition angle and pre-crank prime, since hard starting isn't always a fuel problem. See fuel tuning for the wider picture.
