This guide provides detailed instructions for wiring a B16 engine into an OBD2 Honda Civic or Integra, focusing on alternator compatibility and ECU options. We’ll cover the necessary modifications for a successful engine swap, specifically for 5-speed manual transmissions.
Understanding OBD2 and Engine Wiring
Before diving into the specifics, let’s clarify some terms:
- OBD2a: 1996-1998 Civic / 1996-1999 Integra
- OBD2b: 1999-2000 Civic / 2000-2001 Integra
- EWH: Engine Wire Harness
- PnP: Plug and Play
It’s crucial to understand that OBD1 and OBD2 engine wiring harnesses are not interchangeable. OBD2 harnesses are one-piece, while OBD1 harnesses are two-piece. You cannot use an OBD2b harness in an OBD2a car, or vice versa.
B16 Alternator in OBD2 Swaps: Key Considerations
The alternator connection differs between OBD1 and OBD2 engines. OBD1 alternators have a round plug, while OBD2 alternators utilize a square plug. To address this incompatibility when installing a B16 (OBD1) alternator in an OBD2 car, you have three options:
- Adapter Harness: Cut and splice an OBD1 alternator plug onto your OBD2 EWH, matching wire colors precisely.
- OBD2 Alternator: Use a 1996-2001 B-series alternator, which is OBD2 compatible and will plug directly into your existing harness. This is the easiest solution.
- Internal Plug Swap: Disassemble the OBD1 alternator and replace its internal plug with one from an OBD2 alternator. This requires more technical skill. https://honda-tech.com/zerothread?id=461376
Distributor, Injectors, and IAT Sensor
Besides the B16 Alternator Obd2 considerations, you’ll need to modify the distributor, injector, and IAT sensor plugs:
- Distributor: Use a 1996-2000 B-series VTEC distributor for a plug-and-play solution. Alternatively, adapt the OBD1 distributor plug to your OBD2 harness.
- Injectors: Use 1996-2000 OBD2 injectors for a direct fit. You can also modify the OBD2 injector clips to fit OBD1 injectors.
- IAT Sensor: Either adapt the OBD1 IAT plug to your harness or modify your intake arm to accommodate your existing OBD2 IAT sensor.
ECU Options for B16 Swaps
You have several ECU options, each with pros and cons:
- JDM OBD2 ECU: Easiest installation (plug and play) but has a speed limiter and won’t pass US emissions tests.
- OBD1 ECU Conversion: Requires a jumper harness and a VTEC pressure switch (VTPS) but offers greater tuning flexibility. Won’t pass emissions.
- US OBD2 ECU: Requires addressing the Crank Fluctuation Sensor (CKF) issue with a bypass. http://technet.ff-squad.com/ckftrick.htm Potentially allows for emissions compliance.
Model-Specific Considerations
While the general principles apply to both Civics and Integras, some model-specific differences exist, especially regarding the IACV (Idle Air Control Valve) wiring. Refer to the original article for detailed diagrams:
- 96-98 Civic IACV Wiring: http://www.ff-squad.com/tech/wiring/wiring.96-98.jpg
- 99-00 Civic IACV Wiring: http://www.ff-squad.com/tech/wiring/wiring.99-00.jpg
Successfully swapping a B16 engine into an OBD2 chassis requires careful planning and execution. This guide helps navigate the complexities of wiring, particularly focusing on the b16 alternator obd2 challenge, ensuring a smooth and functional engine swap. Remember to consult model-specific diagrams and resources for detailed instructions.
