Our site is not fully compatible with Internet Explorer. We strongly suggest using Google Chrome, Firefox, Safari, or Edge.

FT450/550 4 Cylinder Universal A Harness


Shipping Cut-Off:  USPS 9:30am EST / UPS 1:00pm EST

  • The FuelTech Universal 4 cylinder A harness is a great addition to any 4 cylinder build and can be used with both the FT450 and FT550 ECU’s in a complete plug and play style. It is to suit 4 injectors and 4 individual smart coils, wired in semi-sequential fuel injection and wasted spark ignition (full sequential requires the FT550 ECU and the 4 Cylinder Universal B Expansion Harness). It can be used with high or low impedance injectors; low impedance requiring the use of a peak and hold driver, high impedance requiring a peak and hold jumper harness (both sold separately). The harness is set up for either VR or Hall effect cam and crank sensors and includes 3 relays with built in fuses for main electronics, injectors and coils. The universal 4 cylinder A harness has a label for each connector and the insulation is heat, moisture and oil resistant.
  • FT450/FT550 4 cylinder universal harness Manual

Technical Specifications:

  • 4 EV1 injectors
  • 4 Smart coils
  • FuelTech Peak and Hold external drivers ready
  • FuelTech WB-Nano O2 ready
  • GM style intake air temperature sensor ready
  • GM style engine temperature sensor ready
  • 2 pressure sensors ready for fuel, oil / another 0-5V sensor
  • Extra output connector for generic use
  • Crank and CAM connectors (hall and VR options included)

This harness was designed for systems with up to 4 injectors, 4 smart coils and a FuelTech Wideband Nano O2 with Bosch LSU 4.2 sensor. It's setup to run semi-sequential or multipoint injection and wasted spark. It is already wired for use with a FuelTech Peak and Hold driver when using 4 low impedance injectors. When using high impedance injectors, a Peak and Hold driver is not needed and in this case, only a bypass connector is required (jumper included). There are 3 separate relays to power the whole system, separating the injectors and coils from the electronics. To activate coils and injectors relays the Blue#6 output must be configured as Fuel pump or RPM activation.

*This is only the A harness which is all the FT450 requires.
To use this harness with the FT550, the FT550 4 Cylinder Universal B Expansion Harness is required in order to use all of the extra inputs & outputs.