Crank pulse width

[Joel_E]

So how big of an injector can you go to before you have to start reducing crank pulse width?? I've changed injectors several times but I've never changed those numbers without any problems. Just curious what other people are doing. Thanks

[Eric Marshall]

Joel, it depends on the injector and how "picky" you are about the way the car starts.

You could leave the stock cranking values all the way up to 83# injectors, but it won't be a nice clean start. The engine may cough a little before it fires up, or you may find that a spark plug got fouled and it will miss for a few seconds upon startup. It also may crank longer than necessary before firing.

In general, you can reduce the cranking pulsewidths by the same percentage of the injector size increase. For example, if you go from a 28# injector to a 55#, then cut the cranking pulsewidths in half. Not all injectors will follow the same rule, but it will get you in the ballpark, and experiment from there.

For those that don't know, neither the cranking fuel nor AE is affected by injector constant changes. Thats why you have to adjust the tables manually.