Distributor Conversion

this is an article on how to convert your OBDII USDM H22a4 to be able to use an OBD1 USDM H22a1 or H23a1 Distributor. Reasons to do this include: the ability to change base timing (as you should know, on OBD2 H22's, ignition timing is all ecu based and the distributor cannot be adjusted) and the ability to make use of aftermarket, adjustable cam gears. On h22a4's, you cannot make adjustments to the exhaust cam gear without getting a CYP check engine light.

The OBDI external coil distributor is an 8 pin male connector. The OBDII distributor is a 4 pin connector. This 4pin connector houses the terminals for the CYP P, CYP M, and ICM.

to do this in a sort of nice way, you must first make your harness from the CKP plug on the engine harness and run your wires to the new 8pin female connector. If you dont have access to these, you can likely go to the junkyard and snag them off any 92-95 honda you see. You want the pins from the connector as well, so just cut the whole connector off the harness with enough wire to solder onto. You will also need a male 4pin connector. This can be found on the majority of 4 wire o2 sensors.

The distributor conversion wiring is as follows:

• OBDII -----------> OBDI--------> function

• Black...............Blue/Yellow........CKP M
• Red................White/Blue..........TDC M
• White.................WHITE............CYP M
• Blue.............Blue/Green..........CKP P
• Green............Orange/Blue...........TDC P
• Yellow...............Orange..............CYP P
• Yellow/Green.....Yellow/Green..........ICM
• Green...............Green..............ICM

OBD2 distributor:

OBD1 distributor: