Civic VX engine D15Z1 with an automatic transmission swap?
 

Hello all,

I have been reading along and researching this site for a few months now and finally decided to register. Thanks to you all for all the very useful info!!


Now on to my question is:

I have an all stock 92 Civic DX Hatchback with a D15B7 engine with an auto tranny (with AC & PS). I am getting decent MPG for an automatic (29-33mpg mixed city/hwy with AC & PS on) and I was seriously thinking about swapping out my stock D15B7 for a D15Z1 engine from a VX to get even better gas mileage.

With my current job, I drive 4500 miles a month easily, so the more MPG the better! With all the traffic I go through, I refuse to drive a manual transmission (call me lazy).

Now would the D15B7's auto tranny mount to the D15Z1 engine? What ECU would I need install in the car to get better MPG? The stock one that I have in my car now? Or an ECU from a VX model? (sorry I dont now the exact ECU numbers) And what kind of complications should be expected? Also, any idea on what MPG would I get with the D15Z1 engine if it were installed and tuned correctly?

Beside the hybrids, I would like to get at least 40 mpg with an automatic transmission with your normal & rush hour, city/hwy type of driving. Im too busy with work and all to be thinking about FE driving habits.

Thanks in advance!

While the D15B7's tranny will probably bolt right up to the D15Z1 without the least difficulty, getting it all to work together might not be practical short of a custom ECU. All USDM P07 ECUs are for manual transmissions.

There might be a way to put a lean-burning D16Y5 and automatic in an EG hatchback. The HX had an automatic transmission option, but it was a CVT and has a bad reputation for premature mechanical failures. I have no idea if an HX automatic ECU (P2N) would work with a non-CVT EK automatic transmission, but if it did, that might be the best swap option even though it would mean converting your EG to OBDII.

Now that the technical part is over, it's time for my opinion:
Unless there's some underlying medical issue to prevent it, driving a manual eventually becomes so 2nd nature that overall effort that would go into using a manual is miniscule compared to what would be required to swap a D15Z1 and automatic into a EG hb - plus there's the vastly better gas mileage with a 5-spd compared to an auto.

Its possible. They came with autos in Japan, its going to be tough to find a p07 auto ECU. I can get you a vx auto tranny, and I'll see if I can find a ECU.

Physically yes it will bolt up....

But as said before at least all US VX's were manual...maybe Canda or the VEI in other countries came with an auto...but I doubt it...

The ECU and the transmission play a big roll in why the VX gets the MPG it is capable of...you would need to have a custom ECU in order for this to produce the numbers you want, I don't believe any one has cracked the VX P07 ECU code...plus the VX uses some of the same ECU pins that the auto ECUs use so I doubt you would be able to make this work as a simple swap...

I think you would be better off as beb said and look for an auto HX swap and converting to OBD2...which is probably gonna be a decent amount of wiring...you could get a custom engine harness from a company like re-wire just tell them what motor trans and chassis and they should be able to make it f you don't want to do it yourself but you'll pay $$$ for it...but if you are serious about a motor swap and not converting to manual I'd look down the HX and auto route...I converted my auto Del sol to a VX manual and it is a fair amount of work for a novice(if this is your first motor swap I'd suggest getting someone with experience to help or having a shop do it...


Good luck, let us know what you decide...Matt

Its a simple swap if he can find a JDM p07 and auto tranny. It would be plug and play, all he would need to wire is the vtec,egr, egr box, and the 5 wire 02. Why would anyone wanna swap to obd2.. Thats insane.

I have one i will sell it for 200

I won't argue with 78si here, he seems to know more about Honda swaps then most people. The problem you will have here is that you'll never get a JDM ECU to pass smog in CA.

I always forget that you have to smog test in CA.. We don't have to do that yet. (Calgary Alberta, Canada)

With that JDM ECU and engine swap, can I just get it Ref'd by the CA Bereau of Automotive Repair to pass smog?

Besides the auto ECU you'll also need the auto tranny controller that resides under the driver's side dash.

Wiring up the EGR, 5 wire O2, VTEC, and tranny solenoids (yes, the OBD1 auto tranny's are partially electronically controlled) is comparable to converting to OBD2. But due to the complications and lack of info of an OBD2 auto tranny swap into an OBD1 chassis, no one who knows what they're talking about would recommend you attempt it.

I personally prefer auto tranny's but I switched to manual (actually sold my old hatch and bought another) because they get better mpg, they put more power to the ground, and because they are far simpler to swap and interchange parts with.

JDM ECU's are slightly different than USDM. But besides that they are technically illegal because they have a different tune on them. Besides the visual test they most likely would also fail on NOx. You'd have more luck just passing your car off as normal at a regular smog shop. Most smog techs would never notice. A ref would notice immediately.

What Civic's had this? I was looking up a circuit last night in an EG Electrical Troubleshooting manual, and out of curiosity tried to find such an auto tranny controller, but could find no sign of it - not even a tap on the power or ground circuits for one. A spot check of a few automatic EK parts lists (HX and EX) didn't show one either, while as Loserkidwac points out, there are auto tranny control signals coming from the ECU for both EGs and EKs.

Supporting suspendedhatch's statement about a different tune on JDM ECUs is this bit from an article by David Blundell, "Introduction to ECU Chipping":

"Honda is no exception to these rules about tuning. Basis for this can be seen very clearly by comparing European/US fuel and timing maps to Japanese timing maps for the same engine. Japanese have gasoline that is on average a minimum of about 10 octane points greater than gas sold in the US. Comparing JDM and USDM/EDM timing curves generally show the JDM maps having several degrees more spark advance, reflecting the manufacturer's expectation of better quality gasoline."

It doesn't sound like typical P07 is chippable, either, according to the tunning community (FWIW, the JDM D15B VTEC-E used in their ETi - which is the closest thing to the D15Z1 (never sold in Japan) - looks to have used a P84, so the limitations on modifyibility of a P07 may not matter).

There is a TCM under the driver's side dash. If I remember correctly it's a little blue box with a grey plug, held down by two 10mm nuts.

As far as I can understand it, P07's are not currently chip-able because the onboard wideband O2 controller required a different board and different code.

To my knowledge you are referring to the the ignition interlock box that prevents you from pulling the key out in gear...its attached to the plate that covers where the clutch master cylinder would be...

https://www.fuelly.com/attachments/fo...f57a17bc0b.jpg

92 civic dx automatic
 

I just found this thread. I noticed that its been inactive for a few months now, but I found the information very useful.

I have a 92 dx automatic. I have installed a b15b vtec-e jdm engine , P84 ecu and kept stock dx transmission.
When I plug-in the P84 ecu, I can't get the car out of Park. If I plug the stock dx ecu, the car shifts from park. This leads me to believe that there is a transmission control box missing that "suspendedhatch" was talking about. Also, I asume that the JDM auto tranny has electronics and sensors in it that wire up to the P84 ecu to tell the car the gear position.

I heard that the JDM auto tranny is a 4 speed.
There is also some reference of a 7 postition configuration inside the transmission to optimize gearing.

Does anyone know anything about this?
Remember, the JDM transmission I am talking about is for 92-95 EG.
As an alternative, do you think its posible to use an EK 96-00 auto tranny with my set-up?

It would be nice to have the P84 ecu schematic or pinout to confirm this information.

back from the dead....has anyone ever done this build and had it working?