|
External sensors such as Wideband Air Fuel ratio, Boost or Fuel pressure will require additional hardware depending on year model vehicle and how many external signals you wish to monitor and/or be included in the TwEECer log files.
The Ford EEC is not capable of making use of these external signals directly, but when included in your log files, you can quickly see where a lean condition is and needs to be corrected.
On most Ford EEC-IV vehicles the EGR Valve Position (EVP) input or the EEC-V Differential Pressure Feedback (DPFE) input can be used as an analog input, to measure a 0-5volt signal, much the same manner as a Digital Volt Meter (DVM).
The output signal of many add on sensors will be scaled 0-1volt or 0-5volts. This includes most Wideband Controllers which can be used to accurately measure Air/Fuel ratios. Most reading AFR range of 10-20:1, with some variance depending on product.
The Original Equipment Manufacturer (OEM) Narrow band HEGO (Heated Exhaust Gas Oxygen) sensor used by Ford, can measure Air/Fuel accurately only at stoichiometric or 14.7:1. Outside of that, the accuracy falls off very quickly, while being able to report rich or lean, they cannot measure how rich or lean.
Many wideband controllers measure Air/Fuel Ratios of 10:1 to 20:1, with some reading a wider range and others a narrower range. When tuning a super or turbo charged setup, a wideband is required, if you want to keep the engine together. Many are able to display in AFR or LAMBDA and can be used with varying fuel types.
|
