OBD1 motor on OBD0 chassis
 

Hey quick question I have a 91 integra obd0 with a blown motor and I want to swap in my old 92 integra motor obd1 into it.. I dont have time to wait for a harness so I want to know if theres anything more I have to do then switch the dizzy, fuel rail/injectors and I think theres something with the o2 sensor?? Basically what has to be done for this swap to keep it obd0?

Also when switching the dizzy is there a specific way to do it?

Thanks, fletch

well, converting your car to obd1 is easy (for the most part), really all you have to do in this case is switch to the obd1 dizzy, get an obd0-obd1 ecu conversion harness (PM me if you need one) and chipped obd1 ecu or the apropriate stock ecu (pr3 if you mean a b18a/b engine....p61 if you mean the b17 engine).

Reuse the obd0 injectors, alternator and complete engine harness. The only modification to the harness you'll have to do is extend the fan switch (thermoswitch) a 2-wire round plug found on the back of the obd0 engine to its obd1 location which is on the thermostat housing. Its the standard round 2-wire obd1 clip found on the harness a bunch of times. If its a vtec engine you'll have to wire up vtec and a knock sensor if you're using a stock p61 ecu (you can disable the knock sensor if the ecu is chipped).

If you're using a chipped obd1 ecu you can disable the heater circuit on the o2 sensor, so you can just re-use your old 1-wire obd0 o2 sensor. If you're using a stock ecu it's gunna be looking for a heated 4-wire o2 sensor otherwise you'll get a CEL, so you'll have to add the other 3 wires and switch to the obd1 style o2 sensor plug. The obd0 o2 sensor is not heated so its only 1 wire.

What I normally do when switching to an obd1 dizzy from an obd0 dizzy is just de-pin the obd0 dizzy plug on the engine harness side and put on an obd1 dizzy plug. The pins are the same and this is super easy to do, but you can definately solder/heat shrink the obd1 dizzy plug on if you are comfortable soldering. DO NOT just cut and tape the wires together, this is asking for problems half-assing your dizzy wiring.

You're MAP sensor may either have to have the wires extended if the new engine has it located on the throttle body (but I think the integras switched to that in 94+). You can even just re-use your old one and run a vaccum line to it (like it was originally set up).

IF you're just swapping in an obd1 b18a/b engine you sure as hell can just re-use EVERYTHING obd0 from your old engine, including the ecu. You most likely will still run into the fan switch problem that I covered earlier so you'll have to switch the plug and extend the wires.