Frequently Asked Questions Archives

OPTION Coil Drive

These are the primary things to adjust to set up the ignition control system. Distrib Base deg = Adjust this so that the displayed timing matches the actual timing seen on a timing light at low RPM, such as idle,... Read More


The ECU has several functions that “Learn” what the required settings are based on sensor signals. The fuel learns how much correction is needed to achieve the target AFR, at steady state. Cal No-Save 196 = Sometimes, the changes made... Read More


The FiTech ECU for Go EFI systems has a special driver circuit that will drive the fuel pump directly, which means that an external relay is not needed. This driver circuit allows both PWM control (pulse width modulated), and direct... Read More


The Electric cooling fans can be controlled separately. Just a reminder – the system only controls a RELAY. DO NOT CONNECT DIRECTLY TO THE FAN – THE ECU COULD BE DAMAGED, AND DEFINITELY THE FAN WILL NOT WORK. The ECU... Read More


An Idle Air Control (IAC) stepper motor valve is used to open or close a passage in small increments (called “Steps”) that adjusts the amount of AIR going through the throttle. The fuel calculation automatically senses the extra air and... Read More


The system can sense the lambda in the exhaust system from the wideband sensor. The lambda is converted to an approximate AFR (Air Fuel Ratio) assuming that lambda 1 = 14.7:1 AFR. The AFR Targets are used to give the... Read More


The fuel requirements during cranking are very far from the speed density calculated amount. Thus, the fuel is not using that equation during the time between stall and about 450 RPM. The main factor determining the amount of fuel needed... Read More


During certain situations, the injectors can be turned off. At high RPM, the injectors and spark can be cut off at the Rev Limit RPM in order to prevent the engine from overspeeding and causing engine damage. This can be... Read More


A speed density algorithm is used to calculate the fuel injection pulsewidth. The temperature used is called the “In Cylinder Temperature” which is calculated as being somewhere between the coolant temperature and the air temperature, depending on the air flowrate.... Read More


Intake manifolds are going to get wet with fuel while running. This wetness changes with temperature, engine vacuum, and air flow speeds. This wetness also must be supplied in addition to the fuel that is intended to reach the cylinders.... Read More

Page 1 of 912345...Last »