I've been reading a lot and there is a lot of mixed results from doing 1 wire, to 4 wire conversion or even getting a p08 or p84 ecu.

I have a d15b with vtec-e stamped on valve cover
car: 1992 civic vx with 5 wire oxygen sensor and p07 ECU
check engine light comes on sometimes
rpm guage sometimes goes near 0 on the cluster but it runs fine, i can try adjusting the idle screw
i get consistent 42mpg though
this is how i bought the car couple weeks ago


my question is, getting a p28 ecu and convert 5-wire to 4 wire oxygen sensor the best route??
or swap a z6 head onto the d15b and doing the 4 wire convert and p28?

 

I don't quite follow what you want to do here. Can you elaborate?

 

• Quote:

  Originally Posted by deschlong

  I don't quite follow what you want to do here. Can you elaborate?

The VX has 5 wire. The d15b vtec-e didn't come with 5 wire oxygen sensor
it's either a 1 wire or 4 wire?

I can't find the original ecu from Japan on the market. Even with the original ECU, I would still have to convert 5 wire.

Just trying to get the proper set up for this d15b without check engine light about the oxygen sensor

 

According to my Japanese service manual, the JDM D15B VTEC-E had the 5-wire LAF:



Note this is the same as the CDM/USDM wiring:

 

No way!!!! so I just need the japanese ECU for the d15b vtec-e.
The p07 ECU from d15z1 is not meant for the d15b, the rpms are much different and higher.

Is the p84 ECU meant for the d15b vtec-e?

 

If it's a legit JDM D15B VTEC-E with a MT, its ECU was p/n 37820-P07-000.

 

Thank you so much for the help I found someone in Russia selling this ECU. Talking with him now hopefully he can ship to USA.
Again, thank you this cleared up everything. Case closed.

 

Shipping from Russia? Now? With all the sanctions? I doubt it. It's also not clear to me why you couldn't use an American or Canadian, or even German ECU. Aren't all the internals identical? Also, NZ might be a more reliable source.

 

Unless either of you have uncovered info since I've stopped learning about the VX (it's been many years since I was digging)
The JDM D15b VTEC-E is a D15Z1 in the states. The P07 should be fine.

there are multiple different versions of USDM P07's out there, the Cali-spec P07 had 5-wire O2 with lean-burn and EGR disabled for 92-mid93, then mid93-95 had a P07 that was a P28 clone using a 4-wire O2. The 49-state P07 remained the same for 92-95 with only a board revision with negligible performance changes.

Keep in mind that the d15b comes in multiple different versions... P05(non-VTEC), P28(VTEC), P07(VTEC-E), P2J(3-stage VTEC) to name the ones off the top of my head.
You have to know what you are searching for when you start looking for info on that particular engine code. (using the head code tends to work better, see above codes)
There is also OBD0, OBD1 and OBD2 versions.

 

I might risk it can't find another one for sale






The original VX d15z1 going 60mph = 2k rpm
D15b vtec-e 60mph = 2600+ rpm
​also I believe the head is slightly different with internals like the cam probably.
not sure if the d15b vtec-e came with an upshift light, currently it sometimes lights up in 5th gear with the VX ECU.

If I can get the p07-000 this will solve the check engine light and upshift if it came with that. Also might get more mpg maybe.

The engine is running fine and averages 42mpg with the VX ECU. I'm getting some shaking at 1st gear probably needs new clutch.

 

the VX and CX had the same trans ratios, that helped with the VX getting the higher MPG numbers.
That sounds like you have the B000 (EX/SI) trans rather than the A000 (LX/DX/VX/CX)
Or maybe the LX/DX higher ratios (higher RPM on highway)

the gear calculations in the ECU are thresholds, over it but under the next one and it sets that gear, so your P07 thinks that you are in 4th gear, so it lights the shift light.

As I said, maybe the JDM d15b VTEC-E is that different from the d15z1... but I do not think so.
the 5-wire O2 suggests that they were running the lean burn mode, which requires the thinner walled head at the exhaust ports to cool the higher EGTs from the higher A/F ratios used.
The camshaft also has to be correct to run the '12v mode' to get the better combustion chamber swirling at lower RPM.
Does it have an EGR valve?
does it have the same tiny throttle body as the VX?

Sorry, I get sort of worked up when I try to learn more about the VX and it's versions. (VTEC-E in general)

 

Agree w above. Sounds like wrong trans, not wrong ECU. Motor could also not be vtec-e. Look for telltale signs posted above. Better yet, post pics in case it's a Frankenmotor

 

I was trying to steer away from that idea. if it's a d15b (z6) block/trans with a Z1 head.... but yah it's a possibility,
I've seen/heard_of all sorts of strange setups, likely due to left overs from a more favorable swapping of parts.

 

VTEC-E valve cover fits on normal VTEC head. Post head stamps too.

 

Head does say po7-1
Unfortunately the transmission sticker is gone
Intake manifold Appears to be same as VX
​​​​​​

 

It's fairly obvious what transmission you have. Shift at redline in first gear. 40mph is a dx/lx trans. 50mph is a cx/vx trans.
Use a borescope to see the piston code and you'll know the block version.

 

that depends on where your redline is, the VX has a much lower redline. (6500, vs the z6's 7500)


that tiny intake manifold, the 5-wire O2, EGR valve behind the VTEC solenoid and of course the head code. that's for sure a VTEC-E head combo. (commonly referred to as D15Z1 in the US and other parts of the world)
As stated by Chrisfrom1986 above, the pistons would confirm the correct block/head combo.

Even if it's not the right block/piston combo, the VX ECU should run this setup all day long.
The trans ratios would be incorrect, and you may have some detonation due to the higher compression ratio of the non-P07 pistons.
But it should run with no CELs.

Suggestion, if you have not yet... take off the EGR valve and clean everything you can. Doing that that, a valve adjustment and new O2 sensor it made my Z1 run like new again.

Going back to your original post, what CELs are present?