Swapping a 2001 OBD2 B18C1 (GSR) engine into a 1991 Honda CRX DX presents unique challenges. This guide addresses common issues encountered during this swap, focusing on wiring and ECU compatibility. My project involves a stock 2001 B18C1 with a Skunk2 intake manifold, mated to an LS transmission in a clean CRX DX chassis. The car also came with an MSD 6AL ignition, which I’ll likely remove for simplicity.
Wiring Harness Modifications for OBD2 GSR Swap
The biggest hurdle with an Obd2 Gsr Swap into an older Honda chassis is the wiring. I initially used an OBD1 B-series engine harness intended for a CRX, expecting compatibility. However, several key connectors were different:
- Distributor: The OBD2 distributor plug differs from the OBD1 version. This was resolved by swapping the OBD2 distributor connector for an OBD1 connector.
- Injectors: The OBD1 and OBD2 injector clips are incompatible. I addressed this by cutting off the OBD1 injector plugs and soldering on the correct OBD2 plugs.
- Alternator: The OBD2 alternator plug also differs. Replacing the OBD2 alternator with a 1991 Integra LS alternator provided a direct plug-and-play solution.
ECU and Jumper Harness Considerations
My setup utilizes a chipped P06 ECU socketed with a P72 basemap. This basemap has IAB and VTEC enabled, with knock control disabled. Connecting the engine harness to the chassis harness requires an OBD0 to OBD1 jumper harness. This bridges the gap between the older chassis wiring and the modified engine harness.
Potential Problems and Solutions
While the above modifications address the major connector differences, other potential issues might arise with an OBD2 GSR swap:
- Sensor Compatibility: Ensure all sensors (e.g., oxygen sensors, coolant temperature sensor) are compatible with the P72 ECU and its calibration. Mismatched sensors can lead to inaccurate readings and poor engine performance.
- Fuel System: Verify that the fuel pump and fuel pressure regulator are adequate for the B18C1’s requirements.
- Exhaust System: Confirm that the exhaust system is compatible with the engine and chassis.
Completing the OBD2 GSR Swap
This swap requires careful planning and execution. Thoroughly research wiring diagrams and consult experienced Honda tuners for guidance. Key steps remaining in my project include installing the radiator and battery, modifying the DA linkage, and addressing any further compatibility issues. With meticulous attention to detail, a successful OBD2 GSR swap into a 91 CRX is achievable. This combination offers a potent and enjoyable driving experience.
