H22A4 --> JDM H22A OBD2 Concerns - Honda Prelude Forum

sieco187 · 09-03-2011, 12:31 PM

First off hello to everyone as you can see this is my first post here but not my first time to the forum. Also I did search the forum first as well as do Google searches but could not find definitive information about the swap just pieces I have put together through different sources. I am hoping someone here with experience or knowledge can answer my questions.

I know that the crank sensor location on the JDM H22 is in the distributor where ass the h22A4 has it in the oil pump. So I see I have two options

Option1
-Swap H22A4 Oil Pump into JDM H22A for crank shaft sensor (or buy new one)
-Swap H22A4 Crank sensor into HDM H22A
-Swap H22A4 Crank Shaft Pulley so crank sensor can read speed correctly
-Swap H22A4 Crankshaft Pulley (harmonic balancer pulleY)
-Possibly swap H22A4 Distributor into H22A (Unsure)

Option2
-Leave H22A JDM oil pump
-Wire crank sensor wires in JDM distributor into harness

So if I go with option 1 I know it will be a little more time, work and money but basically i converted a JDM into an USDM H22A4. Now I havent rulled out option 2 but my problem is I can find a wiring diagram that says "hey stupid these wires wire up like this". So I am afraid if i do go with option 2 i could create a bigger headache for myself and my mechanic.

If anyone has any experience please confirm that option 1 is the correct or if someone can show me where to find a wiring diagram on how to properly do option 2 without creating more problems. Also I have heard that Option 2 can cause issues with a false misfire engine code, is this true?

Here is one source I have looked at here on this forum for information:help!! H22a4 to JDM h22A swap done on 2001 SH serious sensor problem
I have other links but I dont know what the policy is here on outside links (dont want a suspension on my first post)

Thanks in advance!

minilogoguy18 · 09-03-2011, 02:41 PM

You can save money if you rewire but with the engine out it's kinda easier to do it the other way and you wont have a hacked wiring harness. You also have to change the balance gear on the crank as well but the harmonic balancer doesn't matter, use whichever one is in better shape. If you go with the first option you will have to use your H22a4 distributor and coil.

I'd also change a lot of other things while the engine is out, t-belt, balance belt, cam seals, seals on oil pump, water pump and valve cover gasket. The engine may be low mileage but all the gaskets, belts and seals need to be replaced, if not a week after running it you'll notice it leaking from every seal.

Recently helped someone with a Type S swap so yes, I've got experience with it, we went with option 1 and bought a new oil pump but mainly cause the old H22a4's bottom end came apart.

sieco187 · 09-04-2011, 06:36 PM

Thanks for the reply I do appreciate it. I just found another thread on another forum that details almost all of the differences with picture comparisons and I found that the vtec solenoid should also be swapped because JDM only uses one wire and the USDM uses two wires so i will add that to the list of things to swap. For those interested just google "My H22A4 to JDM H22A Swap thread" and it will be the first link. Did you need to swap the engine harness in order to get a better fitment being it was made for right hand drive or did you leave the JDM one. I also read that if I intend to use the USDM ECU then i should also swap the intake manifold. Is this true because I do intend to use my original ECU and dont have a JDM one?

sieco187 · 09-04-2011, 10:32 PM

Ok I am going to go ahead and put in a new oil pump along with the t-belt, balance belt, cam seals, seals on oil pump, water pump and valve cover gasket and got it all for $160 on ebay. I also just started reading about failing hydraulic timing belt tensioner. I know this affected H22A4 motors but did this also effect JDM h22A motors as well? And last question that is somewhat off topic is before the engine died the clutch (at least i think) would squeak at idle kind of like and old alternator belt but not that loud. When i pushed the clutch pedal in it would stop but as soon as I depressed the pedal it would start up. I could not hear it while driving but I am wondering if anyone knows if replacing the throwout/release bearing while the engine is off would fix that?

Honda4Life · 09-05-2011, 12:33 AM

Just swap the injectors, distrib and oil pump and just make it OBDII and make life easy.

minilogoguy18 · 09-05-2011, 07:54 AM

^He's not converting an OBD1 engine to OBD2, he has a JDM OBD2 engine, they're still different.

Use your H22a4 harness, the RHD one wont work with the car and the VTEC spool valve you'll just have to wait and see, some have the oil pressure switch and some do not. Mine did (OBD1) but the Type S engine my buddy put in a 5g did not. You don't have to switch the entire spool valve body out though, the JDM one's will have a bolt threaded where the oil pressure switch goes and you can just swap only the sensor needed.

Timing belts, water pumps and any oil seals/gaskets I definitely wouldn't buy aftermarket, seals/gaskets ALWAYS leak (trust me I've been payed to replace ones that just got put in) and the timing belt and water pump are just too sensitive of parts to be cheaping out on. OEM only.

sieco187 · 09-05-2011, 09:31 PM

Thanks for clearing that up about the harness and the advice

nikosnoopy · 09-06-2011, 01:33 AM

currently i am doing the same swap you are about to do Sieco 187, i did swap over the oil pump ckp and tdc sensor. but i forgot to swap over the usdm balancer gear (the bigger pulley where the belt goes) and the sensor wasn't reading it. now the motor is in the car, i end up wiring the JDM dizzy. now i am curious, anyone can tell me why when the car starts up fine but once it warms up the rpm starts to lower and the car wants to die out?

minilogoguy18 · 09-06-2011, 05:49 AM

^Start your own thread so that someone who has wired it up your way can help you cause I never have.

h22aluder · 09-11-2011, 10:41 PM

also to save you some time. you gotta use the h22a4 lower timimg belt cover if you were planning on switching the the oil pump.

sieco187 · 09-14-2011, 06:43 PM

Thanks for the advice h22aluder! Also does anyone know if its true that if I intend to use the USDM ecu that I will need to switch the intake manifold from the h22a4 onto the h22a? I am hoping I dont because I was getting a CEL code about the EGR of the old engine that I could not get to go away. Engine is here so work will start early next week.

minilogoguy18 · 09-14-2011, 08:11 PM

All the sensors will be the same, the internet is a dirty liar, find people that have real experience if you can rather than reading the net.

The Type S engine that was put in a BB6 by someone I know had nothing changed other than the things I already posted and the car fired right up and was OBD2.

sieco187 · 09-14-2011, 09:01 PM

Cool thanks again minilogoguy sounds like I got almost all the information to get this swap done right.