H22A8 Convert to OBD1

noob · Post by **noob** » Mon Jul 25, 2016 9:26 pm

Hi all,

I've been doing a lot of research, but there are just a few bits of missing information that I just cannot find. Heres the scenario...

I have a 1995 civic eg, with a D16Z6 chassis harness OBD1. I have a H22A8 engine from a 1999 prelude. I plan on running a D16Z6 OBD1 engine harness with a OBD1 P28 ecu.

Now the engine I purchased didn't come with a distributor, but did come with the engine loom (original H22A8 OBD2 engine harness).

From what I've found the stock distributor from the H22A8 engine (5th gen) was a TD-89U (please correct me if I'm wrong), and a distributor from a 4th Gen 2.2 vtec engine, OBD1 is a TD-60U.

Can I just simply install the TD-60U OBD1 distributor and it will run with my OBD1 harnesses and ecu I have? or will I need to do some additional wiring?

Also the stock injectors from the H22A8 are 290cc saturated from what I've found, so should be able to run those with the P28 D16Z6 harness without the need to add the resistor pack? again please correct me if I'm wrong.

I was planning on cutting the plugs from the original OBD2 harness and then using those on the OBD1 D16Z6 harness for everything else, its just the distributor and injectors I needed some clarity on.

I appreciate you guys are all about your ludes, may not be interested in the EG hatches, but fingers crossed there will be someone here who could answer my question.

Many thanks.

89 UKDM BA4 4WS (resto job!) · Post by **wurlycorner** » Tue Jul 26, 2016 8:36 am

There's a few people on here that have put a 5th gen (OBD2) engine in a 4th gen (OBD1) lude so this has been discussed several times on the forum.

In a lude swap, what people do is swap all the 4g OBD1 ancillaries (distributor, injectors, alternator etc) onto the 5g engine so they can retain the 4g wiring loom. Can't recall if there are also any differences on the other engine connections (sensors etc).

So yes, you need to sling a 4g distributor on there and it should work with your civic OBD1 wiring loom. Same for the alternator and injectors - you won't be able to connect your 5g OBD2 injectors to your civic OBD1 loom (unless you modify the loom). So on that basis, you will also need to retain your resistor box.

@Merlin can correct any of that if what I have said is wrong...

What gearbox are you using? If you're using the lude gearbox, you might also find the vss connection is different to the civic loom? Plus also all cable lengths might be different..?

Couple of other questions (that you've probably already thought of, but in case not) will your civic loom have all the relevant connections for the lude engine? E.g. are you using the prelude intake with IAB's?

noob · Post by **noob** » Tue Jul 26, 2016 9:07 pm

Hi wurlycorner,

First of all thanks for replying so quick!

Great, I'm glad you have confirmed my theory on the distributor swap. Like I said I was 99% sure from everything that I had read, but just wanted someone to confirm it. Just a side note, I checked the workshop manual and looked up the wiring diagram for both the 4th gen prelude and the 95 eg hatch (more specifically the D16Z6 Engine) and both distributors have the exact same wiring....same wire colours etc.

I am fully aware that alot of the connectors will need to be cut and extended for the D16Z6 harness to reach the various sensors etc around the H22A8 engine, no problems there.

The D16Z6 engine had saturated injectors (240cc), and I believe the H22A8 also has saturated injectors (although a slightly different injector size), I dont need to run a resistor pack which is great (only need to run a resistor pack on peak and hold injectors). I would appreciate it if someone could confirm that the stock injectors on the H22A8 are saturated injectors and not peak and hold (or low impedance injectors as they are also known).

I was planning on using the 5th gen gearbox from the same car as the H22A8 engine came from (99 Prelude), the gear selector cables shouldn't be a problem I was already aware I would have to cut into the stock tunnel a little and figure out where to mount the gear stick etc, But the VSS? I havent looked into this, I will do some research, thank you.

I am planning (for the time being) on using the stock H22A8 intake manifold, which does have the IAB's....Not ideal, but I will just simply disconnect the IAB's sensor it for the time being as I have heard the P28 ecu cannot run the IAB's (or its a pain in the ****), I know it will have an adverse effect on low end power (mainly torque), but hopefully Ill pick up a skunk2 manifold soon or keep my eyes open for the single runner manifold from the euro r? (I think its the euro type r's with the single runner, none IAB's, please if anyone could confirm)

Again, thanks for helping out, much appreciated, If you could confirm or assist on the points above, would be great!

Many thanks.

89 UKDM BA4 4WS (resto job!) · Post by **wurlycorner** » Wed Jul 27, 2016 7:43 am

UK ATR also has the single runner intake.

VSS is the vehicle speed sensor.

If you're planning on cutting/modifying the loom then you won't have any issues anyway, because you will already have all the plugs you need on the original prelude A8 engine loom. Most people try to avoid having to do that by swapping all the ancillaries as I mentioned.

Post by **Merlin** » Wed Jul 27, 2016 1:02 pm

If I were you I'd get a set of 4 gen injectors. They might fit your Civic loom and sidestep any issue.

noob · Post by **noob** » Wed Jul 27, 2016 8:49 pm

Hmmm may be a good idea regarding the injectors.... potentially the injector clips are the same as the D16Z6 harness as they are both OBD1, in theory straight swap? just need to check if a resistor box is needed.....fortunately I have a resistor box spare from a previous build so doesn't matter too much if i need to use it.

Thanks chaps.

Lude Generation

H22A8 Convert to OBD1

H22A8 Convert to OBD1

Re: H22A8 Convert to OBD1