I have a obd1 p72 head and an obd2 b18c1 block. I know you can run them together but just have a few questions.. Will I need an obd2 alt. and starter, and then an obd1 'dizzy'? Also, which harness if the most simple route to go to put into my car and which ecu would i use (obd1 or 2 gsr ecu)? I have a 93 SI current swapped with an obd2 LS. Thank you.

 

What harness are you planning on using? Are you injectors OBD1? Also ECU? Basically easiest is to make it all match. OBD1 harness, injectors, alternator, ECU. I have OBD1 everyone on a 98 motor swap that i bought someone changed everything to OBD1 but its in a OBD2 civic. Harness was chopped all over have had to go through and resolder and repin items that were incorrect for knock, crank sensor, etc.

 

My question is which harness can i use because an obd1 gsr harness, unspliced, is near impossible to find. And right now my car is on a p28 with obd2 injectors. But if you're asking about the gsr, nothing yet because i'm going to get everything in a bundle.

 

Use as much of the original wiring as possible. The starters and VSS are the same.

If it's an OBD1 car, a B16 harness will do the job. Even a Z6 harness will work actually, everything is in the same position. You'll just have to wire in the IAB. But you'll need all your components (dizzy alt injectors) to be OBD1 unless you want to splice wires.

If it's OBD2, use as much OBD2 hardware as you can. Just don't use a y7 or auto y8 harness because it uses the 3 wire IACV. All other IACVs, IATs, ECTs are the same, both gens.

The OBD2 IAT is in the intake pipe, if your car is OBD2, I would recommend keeping that.

MOST IMPORTANTLY: DO NOT mix up the IAT and IACV or Purge solenoid plugs!! Many harnesses these are all the same plug and it will FRY your ecu if you switch them. Get a Haynes manual for the car your harness is from, check the diagrams in chapter 12 and make sure the wire colors match the sensors!