What to do now? JDM H23A VTEC OBDII swap into 99 Accord Coupe
Thread Starter
Honda-Tech Member
Joined: May 2005
Posts: 33
Likes: 0
From: Toronto, Ontario, Canada
What to do now? JDM H23A VTEC OBDII swap into 99 Accord Coupe
Well, it's been a bit more than a year since my JDM H23A VTEC swap into my Accord. My original F23A1 motor lost all compression in one cylinder and started spitting oil out so I decided to do an engine swap rather than repair it. This is my daily driver.
The H23A VTEC came from a 00-01 JDM Accord SiR with Auto Tranny. I chose this engine as it shared the most common parts with my existing OBDII F23A... my car is manual tranny.
3 wire IACV
Electronically controlled EGR
I began by using my stock F23A1 ECU but it began throwing CELs (random misfires on all cylinders). At the time, we had no idea and suspected the ECU. I searched for an OEM ECU that most closely matched the JDM H23A OBDII. It was the Euro Accord Type R CL1 which used an H22A with 3 wire IACV and an electronically controlled EGR.
Both ECUs turned out to be unsuccessful which I now know is due to the Crank Position and TDC not being next to the crank / oil pump area. It appears that both my USDM F23A ECU and the EDM H22A ECU both expect the Crank Position Sensor and TDC to be next to the crank / oil pump and NOT in the dizzy.
I ended up getting an AEM EMS with wideband O2 sensor and did the majority of tuning myself with the help of various people in the community providing tuning input. I’ve gotten to the point where today, the car runs ok. I’ve only done street tuning so far.
AEM EMS Problems…
Cold starting
I had major issues cold starting the car. If I plugged either of my 2 OEM ECUs to start the car, it was no problem. If I warmed up the car with the OEM ECUs and then plugged the AEM in, it was no problem warm starting. Finding the right initial starting pulse was very difficult esp. in the winter months. There was also some grinding and what sounded like cranking misfires.
I ended up converting the JDM Internal coil dizzy to a proper USDM external coil dizzy. The start problems went away and I’m still playing with the after start enrichment. Worse case, the car will start after 2 tries. Not a big deal anymore.
Stable Idle
I have been battling this issue for over a year and it’s as good as it gets… but the car still stalls once in a while on deceleration when I clutch into neutral before I get to a stop light. When parking the car, it always stalls when the power steering is assisting. My Idle settings are very exaggerated and aggressive to minimize stalling. I set my idle to 1000. My idle is rarely stable, it moves around at random.
I’m thinking that there may be other contributing factors like dirty throttle body or leaking vacuum hoses. I see many others who have an AEM EMS with Honda’s having similar idle issues which may all stem back to those darn OEM CPK, CYP and TDC sensors. I makes sense that AEM came out with a EPM (Electronic Position Module) rather than trying to tweak the EMS to sort out the bad OEM signals… People have reported that changing these sensors have solved and stabilized this issue.
Solutions I’m considering…
Obviously, this is not a car that I plan to track or race. It’s a daily driver so I’m looking for a solution that makes sense financially.
1. Convert to OBD1 and use a P72 ECU to control IAB and EGR.
a. Not sure if I should use a USDM or JDM ECU. Would the JDM ECU work better with my JDM dizzy?
b. I will need to swap in a 2 wire IACV. Does this require the entire intake manifold to be replaced?
c. I want to pass emissions (as I currently do) so I need to swap in a vacuum controlled EGR
d. Street tuning is easy with the AEM and wideband, what’s it like with Chrome?
e. Sell the AEM (keep the wideband controller and sensors)
2. Install the OEM CPK (Crank position sensor) and TDC at the oil pump location
a. It will be expensive to do but I may be able to recover money selling the AEM
b. Reroute CPK and TDC wires accordingly
c. Use the EDM H22A ECU
d. I could probably keep the AEM EMS if this works well but prefer to get more money back
3. Use the AEM EPM
a. Looks like I’ll need to purchase the pencil coils and some module to fire them
b. Need to keep the AEM so this is the most expensive option
Let me know your thoughts and thanks in advance for any input!
The H23A VTEC came from a 00-01 JDM Accord SiR with Auto Tranny. I chose this engine as it shared the most common parts with my existing OBDII F23A... my car is manual tranny.
3 wire IACV
Electronically controlled EGR
I began by using my stock F23A1 ECU but it began throwing CELs (random misfires on all cylinders). At the time, we had no idea and suspected the ECU. I searched for an OEM ECU that most closely matched the JDM H23A OBDII. It was the Euro Accord Type R CL1 which used an H22A with 3 wire IACV and an electronically controlled EGR.
Both ECUs turned out to be unsuccessful which I now know is due to the Crank Position and TDC not being next to the crank / oil pump area. It appears that both my USDM F23A ECU and the EDM H22A ECU both expect the Crank Position Sensor and TDC to be next to the crank / oil pump and NOT in the dizzy.
I ended up getting an AEM EMS with wideband O2 sensor and did the majority of tuning myself with the help of various people in the community providing tuning input. I’ve gotten to the point where today, the car runs ok. I’ve only done street tuning so far.
AEM EMS Problems…
Cold starting
I had major issues cold starting the car. If I plugged either of my 2 OEM ECUs to start the car, it was no problem. If I warmed up the car with the OEM ECUs and then plugged the AEM in, it was no problem warm starting. Finding the right initial starting pulse was very difficult esp. in the winter months. There was also some grinding and what sounded like cranking misfires.
I ended up converting the JDM Internal coil dizzy to a proper USDM external coil dizzy. The start problems went away and I’m still playing with the after start enrichment. Worse case, the car will start after 2 tries. Not a big deal anymore.
Stable Idle
I have been battling this issue for over a year and it’s as good as it gets… but the car still stalls once in a while on deceleration when I clutch into neutral before I get to a stop light. When parking the car, it always stalls when the power steering is assisting. My Idle settings are very exaggerated and aggressive to minimize stalling. I set my idle to 1000. My idle is rarely stable, it moves around at random.
I’m thinking that there may be other contributing factors like dirty throttle body or leaking vacuum hoses. I see many others who have an AEM EMS with Honda’s having similar idle issues which may all stem back to those darn OEM CPK, CYP and TDC sensors. I makes sense that AEM came out with a EPM (Electronic Position Module) rather than trying to tweak the EMS to sort out the bad OEM signals… People have reported that changing these sensors have solved and stabilized this issue.
Solutions I’m considering…
Obviously, this is not a car that I plan to track or race. It’s a daily driver so I’m looking for a solution that makes sense financially.
1. Convert to OBD1 and use a P72 ECU to control IAB and EGR.
a. Not sure if I should use a USDM or JDM ECU. Would the JDM ECU work better with my JDM dizzy?
b. I will need to swap in a 2 wire IACV. Does this require the entire intake manifold to be replaced?
c. I want to pass emissions (as I currently do) so I need to swap in a vacuum controlled EGR
d. Street tuning is easy with the AEM and wideband, what’s it like with Chrome?
e. Sell the AEM (keep the wideband controller and sensors)
2. Install the OEM CPK (Crank position sensor) and TDC at the oil pump location
a. It will be expensive to do but I may be able to recover money selling the AEM
b. Reroute CPK and TDC wires accordingly
c. Use the EDM H22A ECU
d. I could probably keep the AEM EMS if this works well but prefer to get more money back
3. Use the AEM EPM
a. Looks like I’ll need to purchase the pencil coils and some module to fire them
b. Need to keep the AEM so this is the most expensive option
Let me know your thoughts and thanks in advance for any input!
Thread
Thread Starter
Forum
Replies
Last Post
lithiumus
Hybrid / Engine Swaps
4
Feb 11, 2007 03:28 AM
londonsupra
Honda Accord (1990 - 2002)
1
Jun 17, 2006 11:52 PM
JoWaY
Honda Accord (1990 - 2002)
6
Apr 11, 2005 11:45 PM
