1989 civic DX d15z1/Hf tranny

[cbaber]

Originally Posted by nitebluesky

well hopefully ill figure it out this weekend. Could i possibly hardwire it to the ecm? the 02 sensor. Making the wires really long and just pin it to my ecm? I found this drawing today. i think this will be simple and useful. Here are some pictures and let me know what you think.

You could, but perform the test slownugly posted. It's a lot easier testing a few wires than splicing in a new circuit.

If one of the wires is not conducting, you could hardwire it to the ECU for a quick fix until you can track down the issue in the harness.

[slownugly]

Yup what he said ^


Those diagrams you posted look accurate

[nitebluesky]

Well i tested the o2 sensor and my harness is reading it but somewhere from the o2 to the ECM there is a break in my harness, but my 02 is getting a read. So my harness which is not a VX harness is bad or a loose wire. I am looking into getting a harness tomorrow from some guy for $30 bucks. NOW i have two 02 sensors. So when i get the chance i am going to hardwire from my o2 directly to my ecm and see if that works before i start hacking. In my mean time i am going to get the harness anyways because its a such a good deal. What should i look for in the harness that is specifically for a VX? I hope this harness checks out tomorrow. ill be testing this thing in a couple more weeks maybe during thanksgiving break. For now i get crap mpgs with black dots from running so rich in the back of my bumper and trunk.

[slownugly]

I thought you were running a vx harness. Anyways the biggest tell tale would be to look for that 7 wire o2 sensor plug. Which color wire had an open? If you do hardwire it remember not to cut the o2 sensor plug because the resistor is in there. It must be wIred after the plug

[construct1]

I have a z1 in a crx with an HF trans they do bolt right up for those who asked
Where did you get your obd0-1harness spend the money boomslang made one for me call them and tell them your putting the vx in they will send you the right wires to solder up have not had a problem with that.
Let's face it the z1 gets good milage but is fussy mine bucks etc like everyone else I've gotten 47mpg doing 75 from Chicago to florida, none less then 41 but not better then 50 driving like grandma. Been a yr since swap and 18k plus miles. My plugs constantly look like their fowled out only thing I'm missing is the cat.
Know a guy with a 100%stock vx same bucking hesitate problem solved with a p28 and a 4 wire o2 with p07 map no more lean burn. Even master Honda techs can't figure them out. On the dyno when the bucking hesitation came on is when lean burn was kicking in

[construct1]

I got lucky had a vx wire harness cut the 5 wire o2 sensor connector off then soldered my extra wires that were made from the obd 0-1harness to that sensor then pluged in the new o2 and ta-dah no problems since
Your cheap eBay harness sounds like the problem get a new one made for a p07 ecu with the wires for our 5 wire o2

[slownugly]

Construct1- does your 02 say A09 on it? Some sensors will cause the lean burn stumble. My old one did but it didn't throw a code. Put the a09 sensor in it and it goes in and out of lean burn like butter. Increased my mileage at the same time.

[construct1]

I've heard that one pretty sure mine is a08... I've just come to the conclusion you can have everything right on these and still get that stumble...I know a shop by me that tried every thing that's when they got rid of lean burn... I believe its in the ecu some just work better then others... Let's see I could run a cat get the ao9 o2 pretty sure it would still stumble and I'm out another 500 plus... Its a gamble with the o2 how do you order it telling them I need a ngk-ntk ao9 5 wire. Had the right numbers they don't know Thiers an ao8 and an ao9 only way to tell is its on the sensor it self not on the box

[slownugly]

Yea a08 is def not the right one. I had a brand new a08 and it stumbled terribly. There's a forum member who bought one from an eBay seller for 140 shipped and it had a09. Might be worth a try.

These systems are very picky and even wen they work properly they do have that power loss when it enters lean burn. Try unplugging the o2 and see if the stumble goes away.

[slownugly]

Blue sky- any luck getting this straightened out?