I put a d15b7 in my 92 cx and am having idle issues - rough during warm-up and sits at 1400 after warm-up. There's an unconnected port off the TB/IM and I have no idea where it should lead to.

Here's a picture (not my car). It's not very good but not too many people take pictures on their d15b7 bay.


Where does it go? All there any other differences between the b7 and b8 that aren't obvious and could be causing idle problems?

 

That's the important vacuum hose that attaches to the MAP sensor located on the firewall. Did the previous engine have the MAP sensor on the TB? Do you have a MAP sensor CEL code?

 

Yeah it was on the TB and I do have the code. I'll go to the junkyard and rip one off a dx tomorrow. What should I take besides the line to the TB, the sensor/wires, etc? Where does it plug into the engine harness? I'm using the d15b7 one but I don't think I have any plugs unplugged. :/

Thanks a lot.

 

the D15B harness has the wires coming directly from the ECU, though the firewall to the MAP sensor. So you wouldnt notice a plug on the regular engine harness that was unplugged.

 

You still have the TB MAP sensor connector for the original engine, right? Just plug this 3P connector into the new firewall sensor that you plan to get.

 

I have the whole engine harness from the b8 (in a box, I'm using the b7 on the engine) but the engine (and map sensor) is gone.

So the b8 map sensor plug will fit a firewall-mounted map sensor?

Will the b8 ecu harness have wires for the 3 pins I need or will I need to to run them myself?

I know the MAP sensor wires are D17, D19, D21 but which is which?

 

Your MAP sensor plug should work with the firewall MAP sensor. Just note the wire color differences (see diagram). It does seem, however, that you will need to run MAP sensor wires through the firewall to the ECU.

Here's how the MAP sensor wires pin to the ECU:

Grn/Wht or Grn/Blu ---> D21
Yel/Red or Yel/Grn --->D19
Wht ---> D17

 

[off topic] Hehe .... Technically, you've also just upgraded to a CDM 92-95 CX. (All CX's in Canada came with the D15B7) [/off topic]

Hey, since you're in Wisconsin, you should think about my Heated Seats upgrade.

 

Thanks all. I'll let you know how it goes.

 

I got the sensor and it runs perfect, no CEL. Thanks a lot all.

I actually didn't need to run the wires through the firewall to the ecu either. I just took the 3 map sensor wires from the b8 harness and plugged them into the master plug near the battery/fuses.

 

glad that you got it fixed.