searched for this for a little while and found on ff squad a pic (link below)
i have a obd2b d16y7 in my 98 ex using the obd2a harness and conversion harness to run the y7 ecu, so if i do what this pic shows will it work, little confused cause they only talk about then in reference to obd1 change overs, thanks


http://www.ff-squad.com/tech/wiring/...-98_a-plug.jpg

 

anyone? just need to make sure im not going to do the wrong thing here

 

ok still kinda need this info, right now i have the 2 matching wires connected and the extra i have nothing on because i think i remember this being a ground wire??? not sure but the car is idling fine and normal but when it is reved to about 1500 it flutuates but then when you rev it to about 2000 and up it is normal again... should i ground the extra wire or am i going down to total wrong path, need help please

 

OBD2a:




OBD2b:

 

thanks for the diagram but im still not really sure what it all means and what i need to do cause my harness has the 2 wire plug and my engine has the 3 wire plug, i just dont want to mess anything up

 

The valve needs to match the type of ECU you have. If you have a D16Y8 VTEC and manual transmission setup you need to replace the valve with a 2 wire one

 

I have an obd2b ecu and the motor has a 3 pin plug but the harness has a 2 pin plug, I need to know how to wire up a 3 pin plug onto my harness if it's true that the valve has to match the ecu... The diagrams didn't help really because I can't make sence of them, could you please explain how to wire a 3 pin plug from a 2 pin plug harness

 

So you have an OBD2b ECU in an originally OBD2a car. You want to end up with the bottom diagram that Ron posted, more specifically the diagram on the right side showing the 3 wire valve. Note that it does not show a conversion harness. The final result, after the conversion harness and everything, should be what is shown on the right side of the bottom diagram.

You will need to run another wire all the way from the ECU to the IACV in this case. The harness in the car only has two, and you need 3. This is no big deal. Select some decent wire for underhood use. It does not need to be of a heavy gauge, just similar size to the ones on the IACV plug.

Go to the "B" ECU plug, part of the conversion harness, the plug that actually plugs into the OBD2b ECU you have now, NOT the plug on the other side of the converter that plugs into the car harness. Take the pin out of slot B23-- the wire may be black and blue or maybe not, depending on how the conversion harness is made-- but do note that it leads to the black and blue wire on the car at A12 on the OBD2a plug. Push this pin into slot B6. B6 may not be empty on the stock conversion harness. If it has a pin in it already, pull that one out and tape it up so it can't short.

Connect your new wire to B15 on the ECU and run it up to the valve location. If the conversion harness doesn't have B6 and B15 already wired, you will need a spare ECU pin from a parts car to push into the ECU plug and make the connection at B15. If it does, cut the wire from B15 and splice it to your new wire instead.

Under the hood, you of course need a 3 wire IACV plug from a parts car to plug into your valve. Connect the black and blue wire of your car's harness (and 2 wire IACV plug) to pin 3 of the new 3 wire IACV plug, in other words splice your car's black and blue wire to the plug's black and blue wire(*). Similarly splice the yellow and black wires so yellow and black goes to pin 2. Finally connect your new wire that starts at B15 to the orange wire on the IACV plug (pin 1)

(*) After going through the car harness and the modified conversion harness, this is the wire that starts at B6 on the ECU, it is the wire you moved. It used to start at B23 but that would be the setup for a VTEC ECU and a 2 wire valve, which you don't have.

Note that rather than a new wire, you have some extra wires related to the VTEC, which you aren't using now. But finding them will make the job more complicated, and also you would no longer be ready to swap back to a VTEC engine if you ever wanted to.

 

Listen to Mk. He is leading you to the Promised Land. Mk please change your forum title to HCF President. You can do this by going to the User CP.

 

im going to do this first thing tomorrow, thanks so much for the help!!! thats exactly what i needed, im not to good with the wiring but this is great!