GM > Engine > Fuel Control > Transient Fuel

Transient Fuel
The Transient Fuel Tab contains parameters related to Transient Fueling. Due to the port injection configuration of the LS1 engine, a model of fuel transfer from the injector to the cylinder is required. Fuel is not injected directly into the cylinder, but into the airstream aimed at the back of the inlet valve (and port walls) where it subsequently puddles and then boils off (evaporates) into the incoming airstream at a certain rate. The amount of fuel pudding and boiling must be accounted for to ensure optimum fuel delivery. This is particularly true during throttle transients.

During positive throttle (MAP) transients additional fuel must be injected than commanded to account for the fact that not all the fuel injected will make it into the cylinder. If additional fuel were not injected a lean condition would result as more fuel is puddling on the valve and port walls rather than entering the cylinder.

Conversely, during negative throttle (MAP) transients, less fuel needs to be injected than commanded to account for remaining fuel that is still boiling off the walls. If less fuel was not injected a rich condition would result.

Transient Fuel Qualification

Warmup Transient Fuel Correction
Warmup Transient Correction (also known as Stomp Compensation) is used to add additional fuel to transients during engine startup conditions. This is to adjust for conditions of inlet port and valve components not being up to satisfactory temperature. ie. extra fuel puddles on a cold intake.

Transient Fuel Film Mass Transfer Calculation

Transient Fuel Compensator Gain Calculation