The 1JZ-GTE VVTi engine swap into an IS300 is a popular modification. One common question that arises during this swap is the location and functionality of the OBD2 port. This guide addresses common concerns regarding the OBD2 port in a 1JZ swapped vehicle, specifically focusing on the JZS171 engine.
OBD2 Port Location and Wiring in a JZS171 Swap
The JZS171, originating from a Toyota Crown or Mark II, utilizes a different wiring harness than the IS300. While the physical OBD2 port location in the IS300 remains unchanged after the swap, the wiring needs to be addressed for proper functionality.
The JZS171 ECU pinout is surprisingly similar to the JZX110 (another popular chassis for this swap). This simplifies the wiring process, making it a direct plug-and-play for the most part. However, repinning the body harness connector to the JZS171 ECU is essential. This process requires patience and careful attention to the wiring diagrams. Specialized tools for depinning and repinning connectors are highly recommended. Expect some leftover wires from the original IS300 harness; these can be safely taped off.
Gauges and Functionality After the Swap
After the wiring is complete, some gauges may not function as intended. Notably, the coolant temperature gauge and MPG gauge may not provide accurate readings. Using aftermarket gauges for accurate monitoring is advised. The functionality of the tiptronic transmission, if retained, should remain unaffected, but ensure a thorough fluid change and filter replacement. Consider upgrading to a higher stall torque converter for improved performance.
Addressing Potential Issues: J-Pipe and Fuel System
Deleting the J-pipe can improve exhaust flow. To optimize engine performance, using a piggyback system with MAF clamping capabilities or installing an airflow straightener is recommended. If upgrading to a larger turbocharger, these modifications may be less critical.
The fuel system requires attention as well. Swapping to an Aristo fuel pump hanger is a highly recommended upgrade to ensure sufficient fuel delivery. Utilizing the 5/6th line for the return is crucial. The fuel light might flash after the swap; a simple workaround is covering it with tape.
Air Conditioning Functionality in a 1JZ Swapped IS300
The factory A/C system will not function directly with the JZS171 ECU. A custom solution, often provided by aftermarket specialists, is necessary to integrate the A/C system with the swapped engine. This typically involves a control box that manages the A/C compressor engagement and idle-up functionality.
Final Thoughts on the 1JZ Swap
The 1JZ-GTE swap offers significant performance gains for the IS300. While the wiring and some ancillary component adjustments can be challenging, the results are well worth the effort. With careful planning and execution, the swap can be completed in a weekend. Remember to upgrade to a Limited Slip Differential (LSD) for optimal handling.
