88 crx Hf - **VTi** swap

[88hf]

oh, plus you get cupholders.

[re-evaluating]

Hey shorty_boy, Not to hijack this thread but I don't have enough posts to pm you. I am a long time lurker that works 12 hour midnights and spend a lot of time searching and reading not much posting.

I have been researching for months and considered doing this swap but I really don't want to rip out the dash harness and all of that if not completely necessary. I have a 90 CRX Si with HF motor and trans and the motor is tired.

I don't know which direction you went wiring your car but wondering if it is possible to use the 3 stage engine harness and re-pin or adapt the chassis harness to work with the 90 dash etc. I know I would have add some things like a LED or something for lean burn indicator but not sure what else would be required to make it run.

Any input from you or 88HF (whom ever) would be appreciated.
Thanks in advance Dave

Originally Posted by shorty_boy

And now that ?I have been back for a week, I have been working on the swap. I have the engine together and painted, I have the main wiring harness completed. I an now trying to make a sub harness so that I do not have to snip wires on the stock HF harness.

I cannot wait until I can fire this thing up. Everything was going great until the I realized that the P2J takes on some of the function that the CRX under-dash harness controls.

[88hf]

I think you can just use an obd0 to obd2 conversion harness and most of the mpfi engine harness is the same i believe. There are some wires that have to be added for stuff the obd0 engines didn't use. In all its about the same as a d16y8 or d15z1 conversion there is a difference in having a second vtec solenoid and 3 wire iacv. Good luck.

I might be getting another crx tomorrow. Will make 2 hfs, 1 si and the insight.

btw the common harness is the other way around obd2 to obd0 whereas what you'll need is an obd0 to obd2. They are opposites. Don't buy the wrong one.

[re-evaluating]

Thanks 88HF I hear you on the other way around harness make sense. I have a stock JDM 3 stage harness lined out my concern is what else from chassis to JDM obd2 ecm do I need to worry about?

Hawgin' all the CRX up are you? Congrats, I have a couple Si's

Thanks for the input. Dave

Originally Posted by 88hf

I think you can just use an obd0 to obd2 conversion harness and most of the mpfi engine harness is the same i believe. There are some wires that have to be added for stuff the obd0 engines didn't use. In all its about the same as a d16y8 or d15z1 conversion there is a difference in having a second vtec solenoid and 3 wire iacv. Good luck.

I might be getting another crx tomorrow. Will make 2 hfs, 1 si and the insight.

btw the common harness is the other way around obd2 to obd0 whereas what you'll need is an obd0 to obd2. They are opposites. Don't buy the wrong one.

[shorty_boy]

Since I have a stock HF, I reused as much from the HF as possible. Once you get rid of the resistor box, that gives you about three more wires to use. Basically I converted the HF to OBD2a by reusing all of the HF's stock harness. I did have to run another wire for the second VTEC harness but you also gain a wire because the D15z7 does not use an Absolute Pressure sensor. I am still working on this write up. Work has been a pain. I should have done this as I worked on the car. If you can find an HF cluster, you can use the shift up light as your lean burn indicator.

Basically, I made the harness for the D15z7 into a two piece that plugs into the HF stock plugs on the shock towers. I then made a converter adapter so that you can plug the HF's ECU plugs into the OBD2a ECU plugs This allows you to unplug the OBD2a harness and connect another OBD0 engine with out cutting wires or modifying your HF harness. The SI wiring is going to be a little different inside the cabin than the HF, but if it has an HF engine, I assume all of the that conversion has been done correctly under the hood.

[re-evaluating]

Originally Posted by shorty_boy

The SI wiring is going to be a little different inside the cabin than the HF, but if it has an HF engine, I assume all of the that conversion has been done correctly under the hood.

Here in lies some of the problem. None of the HF's in my area are still in stock form so I found a nice body to start my build it ended up being a 90 Si.

I previously had found an HF D15B6 engine and trans that was to be in "good original condition".

A friend was out of work he said he could do the swap and am working a ton of hours 12 hour nights so it sounded good to me. He was to do other repairs on the chassis as well all of which are completed and excellent. He told me wiring was not his strong suit ahead of time so I was kind of prepared to get some of the headaches.

He tried to start the car with the HF engine harness that was attached to the engine connected it to the Si chassis harness and that as we all now know doesn't work at all. I traced out the wiring with him and determined he needed to use the Si harness.

Well he got the engine running using the Si harness. It has several codes in it and is in limp mode best I can tell but I have only spent a short while looking into it.

Codes are 5,9, 15 I think which are cylinder position, crank position, and igniter for what it is worth.
I know these could be caused by a bad distributor (we used the TD 01U from the HF) and I am thinking that may be the problem as it is a known good. I think my buddy tried to re-pin it to work with the HF harness so that may also be it, and the first thing I look at.

Worst thing is unfortunately the motor smokes pretty bad so it seems it isn't in as "good condition" as promised.

I do plan to at least try and straighten out the issues before I do anything else but this motor will not be in for long. I don't know of anyother changes made or needed to be made to the chassis harness to make the D15B6 run in the Si chassis so input is appreciated. I have done a lot of searching but few swap this direction almost no one it seems.

I had been considering the 3 stage swap for a while so I may move in that direction sooner than expected.

If anyone has any thoughts about my issues I can start another thread or someone can pm me. Any and all information and thoughts are appreciated.

thanks Dave

[some_other_dave]

A place with lots of CRX knowledge, including pointers to the ECU codes:

CRX Community Forum • Index page

-soD

[re-evaluating]

Originally Posted by some_other_dave

A place with lots of CRX knowledge, including pointers to the ECU codes: CRX Community Forum • Index page
-soD

Well for what it is worth I have gotten misinformation from so many places I can't tell you including that site. I have looked literally at least a hundred times or more to confirm which distributor the HF uses. Everywhere says the 1.5 engine HF included uses the TD 01U distributor. That is completely incorrect. The reason I was getting those codes is because that distributor has only 2 pick ups in it and the HF requires 3 just as the Si does. I installed and properly wired a TD 18U distributor and magiclly all the codes are gone the engine runs smooth and 90% of the smoke is gone.

I still don't understand why the Helms service manual and the Honda electrical manual have completely different pin outs for the ECU or at least different number locations.

Oh well I will have this car on the road very soon, just need a little exhaust work. Thanks Dave

[some_other_dave]

Unfortunately, there will always be misinformation out there. Glad to hear you figured out what the problem was!

-soD

[shorty_boy]

I agree with some other dave, but i can tell that you did not talk to the right people on the "community" or your question was asked in correctly. The "community" is one of the last outposts for decent conversation and help on the internet as far as engine swaps and/or crxs. I have been a member for a while now and have never been led astray. Plus most of the information that you seek is stickied in the "stock garage" on the forvm.

I am glad that your issue is fixed. Now that you have the HF engine running off of the Si harness, you would only make the mods required for the OBD0 Si to OBD2 conversion. Since you still have a CRX, i highly recommend that you join the community.

To keep this post on topic, I am still trying to track down an IACV from a manual OBD2 VTEC Civic. Car is getting consistent 34mpg with a "bad" IACV. A brand new one will cost me 197USD. My junk yard here has nothing newer that '95 Civics and Integras. And none are VTEC.