Going OBD1 from H23A VTEC swap

[lithiumus]

Long story short, I did a JDM 00-01 H23A VTEC OBD2 engine swap into my 99 Accord coupe. After a myriad of problems and small issues, I ended up with an AEM EMS running the H23A.

What is unique about this H series motor is that it uses a 3 wire IACV as well as an electronically controlled EGR (instead of the vacuum controlled on on the Preludes). Unfortunately what isn't unique is that the Crank Position Sensor and TDC are located in the dizzy like all JDM motors.

Both my OEM F23A1 ECU and EDM H22A7 ECUs show cylinder misfires because of the JDM sensors. I'm now realizing that all my woes tuning startup and idling on the AEM may also be attributed to the sensors.

One option I'm considering is going to OBD1. Things I need with questions...

• change my 3 wire IACV to a 2 wire (not a big deal)
• swap the electronic EGR with a vacuum EGR
• OBD1 ECU...

Not sure which is the best ECU to use... will I need a JDM ECU to match the JDM sensors or will a USDM ECU work as well? I've got IABs and I want to continue to pass emissions so the EGR is necessary.

Will a USDM or JDM P72 do the trick? I tuned my AEM EMS to pass emissions and I've got a wideband O2 to help with tuning, I can probably keep the wideband to help with OBD1 tuning...

Thanks for the help.

 

[wadocrx]

You can always got a chipped P28 I suppose. Try calling Hasport Hasport Performance, Inc. or LocashRacing.com These shops are right next to mine and they know their stuff. i bought my Hondata S300 from locash, been friend swith him for over 10 years now. If you wanted one of those I'm sure he'd give you a great deal. Tell him Wade sent ya!

 

[ndwood1]

I know this thread is several Months old but, Litiumus, I want to thank you for posting your project. I'm currently Swapping an H23A into my 98 Accord, and staying auto. I'm getting the same CEL for the misfires, I wired my CKP and CYP through JDM dizzy. Pretty sure thats our problem, I've tried the trick the civic guys are using by jumping the CYP to the CMP but . . . that does'nt work to well. And not crazy about the idea of transfering my oil pump housing and sensors. So just checking to see if you or anyone else has found anything out on this. Thanks, & I'll leave you with some picks of my swap.

 

[lithiumus]

Yup. The problem is not so much the CEL in itself, the problem is that you can't throw a CEL during emissions testing. Also, a piston misfire CEL will send your ECU into safe mode in and you will run pig rich and definitely fail emissions. I tried to pass emissions with my original ECU and everything was fine until it threw the cell and started dumping fuel.

Did you get the oringal ECU with the swap? If not, I have my original that I can sell to you but I can't guarantee that it will work. I've got manual so I couldn't use it. The only solution would be to get the original ECU to work which will accept the signals from the dizzy instead of the Oil crank / pump location or retrofit your OEM Oil crank / pump sensors which is a pretty big job. PM if you want to try the OEM ECU.

 

[ndwood1]

Yea I've got the ecu from the h23a but that ecu is for a sport shift and I don't think it will work with my straight up auto trans. Also I'm using my OEM harness so I need a pinout for this ecu so I can move pins as needed. I'd love to be able to use the h23a ecu so I can hook up iab's and not do this oil pump housing, & sensor swap. I'm not sure that's possible with the difference in tranny's though. We don't have emissions testing here so I may end up going obd1 eventually. So much easier to tune and more options when obd1 anyway.