1996 Honda Civic DX into 1996 Honda Civic EX (wiring harness is different) Car idles

[needhondacivichelp]

So i bought a 1996 Honda Civic DX engine and put it into my1996 Honda Civic EX.

There is one wiring harness plug by the air intake that is not compatible with the engine (I have more details and specifics if somebody could help it would be greatly appreciated as im having trouble getting to work without a car.)

Basically the wiring harness for the EX isnt compatible with the DX and I need to know how to swap it correctly.

The car starts and idles fine but when u hit the gas it doesn't rev and sounds like its about to stall.

Please TXT me 315-573-9071 (kyle)

 

[needhondacivichelp]

Basically I have a D16Y7 engine and (oops) have it in a car that originally had a D16Y8 engine...

How can I get this car to run?

 

[AHHVTEC]

are you using the dx ecu or ex and do you have any check lights on

 

[needhondacivichelp]

Hey AHHVTEC,

I am using the EX's ECU (the cars computer right?) and the EX's wiring harness with the DX engine etc.

I have the DX computer but not the DX wiring harness.

I dont know about the check engine lights I will check that tomorrow and hopefully post any codes that come up.

 

[tabKola]

DX computer should just plug in place of the EX one. You will have to change the IACV wiring on the harness to get the car to idle correctly.

Basically you do the above in reverse at the ECU plug. You then have to take that plug you found that isn't compatible (should be 2 wires) and connect those wires along with your new orange wire to the light green sensor on the throttle body. All of this is assuming that the EX was a 5 speed originally.

 

[AHHVTEC]

yeah run the dx ecu.

 

[GlassHeadlights]

I'd use the Y8 intake mani if you still have it too.

 

[needhondacivichelp]

Thank you very much, though it was an automatic at one point (is manual now) i am being told it was automatic because one of the wires that runs along the power steering was cut because that wire is meant for automatics.

So i run a new wire from the ECU to the uncompatable green sensor along with the other two wires. Also switching those wires on the plug. (my guy is telling me he didnt get the ecu like hes supposed to but assuming i do get)

How do i hook the wires to the green sensor? Cut it and connect the wires directly or stick the wires in the three holes?

Thanks again.

 

[josh_crewdson@y]

put the y8 manifold, off of the motor that was in the car originally, on the motor. problem solved.

 

[needhondacivichelp]

Is it possible to wire up the Y7 motor etc with the Y8 wire harness and Y8 ECU without getting a Y8 intake mainfold or switching computers?

And do i need to make any modifications or is the Y8 manifold plug and play with the Y7 because Its to a Y8 computer.

 

[GlassHeadlights]

Both motors work on multi port fuel injection so the computer won't notice any difference or look for any more input, just a lot better air flow.

Make sure you have a manual intake mani, an auto one will not work. (You need the little holes)

 

[AHHVTEC]

the ex ecu will throw a code because it will be looking for vtec

 

[tabKola]

Also the fuel maps will be wrong due to the different cam profile and the Y8 uses larger fuel injectors.

 

[needhondacivichelp]

Y7 into Y8 car Update!!!

1. I got a Manual Y7 ECU (automatic throws a code because i have a manual transmission)

2. I Did the 2-Wire to 3-Wire IACV Fix.

I did the Y7 to Y8 in reverse like in the picture that tabKola posted. (moved A12 to A14 and added a wire at A13, attached 3 wire plug black to black, orange to new wire, and yellow to green.

3. I Put back the Y7 intake manifold on. (i dont have Y8 manifold)

4. Plugged everything up and I started the car...

Problem:

Car Idles from 1000rpm to 2000rpm back and forth forever.

Check Light Codes P1509 and P0505 for the IACV.

Have already tried:

Checked wiring and plugs, they are all on correctly.
Checked for air bubbles in coolant system, no more bubbles.
Checked for vacuum leaks.
Took apart throttle body and IACV and cleaned them both with Carb Cleaner.
Reset ECU a few times.
Drove the car for two days. (problem only during idling)
Let car idle for 20 minutes with no self correct.
Unplugging IACV doesnt change anything.
Unplugging MAP sensor makes idle go crazy at 1.5k rpms.
Plugging in Y8 ECU makes it act like i unplugged the map sensor.

 

[monotech]

Use a test light and see if you are getting 12v+ on the yellow/black stripe wire if not you will have to run a 12v+ wire spliced into that wire. This should fix your problem unless you have a bad EACV sensor.