EFI+Harness

toc The **EFI Harness** (often referred to as the **wiring harness**) is a large collection of wires and electrical connectors connecting the ECU to various components in and around the engine bay.



On the Z32
The Z32 harness connects the ECU to several components in the car, including but not limited to:
 * Fuel Injectors
 * PTU
 * Crank Angle Sensor
 * Engine Temp Sensor
 * Gauge Cluster
 * MAF Sensor
 * O2 Sensors

Due to the extreme heat in the engine bay, the EFI harness connectors are prone to becoming brittle and breaking, leading to intermittent connections that cause poor performance (or even none at all!). It's common practice to replace the EFI harness, though it can be expensive and somewhat difficult to do. Note that there are some differences in EFI harnesses depending on the model years for which they are made. For example, an EFI harness for a 95TT will have new-style injector connectors, while one for a 90TT will have old-style connectors. Some owners who have retrofitted new-style injectors to their old-style engines prefer to replace the wiring harness at the same time to have compatible injector connectors, without the need to splice in new connectors.

Replacement
As the original EFI harnesses become brittle and corroded, many owners opt to replace the wiring harness. It can be done with the engine in the car, with some difficulty. here are some of the tough parts and some tips: Alternatively, some find that only a few connectors are broken/brittle on their EFI harnesses, and opt instead do depin and replace connectors for the coilpacks, or splice new connectors for the fuel injectors.
 * The brackets holding it to the firewall ---> Having the intake manifold off makes these brackets easier to access, but they're just a series of 10mm bolts.
 * The white connector (which goes inside the car) can be troublesome to fit through the hole > Some depin the connector, then repin it once it's in the car (be sure to label the wires!), others will bend or "persuade" the opening a bit to fit the white connector through.

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Parts (Category) Electronic Fuel Injection (Category)