Rosko

iTrader: (1)

Sounds like you dont have the H23a bluetop like you think. There is a non-vtec jdm H23a, just like your original mortor (h23a1) it sounds like this is what you have. The valvecovers between your original motor and the jDM bluetop vtec motor would NOT be interchangeable so this leads me to believe that you H23a is just a JDM "H23a1" and wont have vtec.

Sorry about the problems, I bet it sucks when someone else works on your car when you can't be around to know whats going on.

732xghost

so my friend blew his balance shaft on his blue top.

h23jdmlude

i have this mystery motor (jdm h23a blue top with vtec) and have the jumper to do the obd2 to obd1 conversion but i need an obd1 ecu, does anyone know which ecu i should get to run the motor to its full potential, ive heard a p13 and ive also heard of a p28 working, but i have no idea which ecu i should use, right now i have an obd2 jdm ecu with the immobilizer system and i kind of dont want that anymore. does anyone know which ecu i need to get??

Seismic

The P13 will be able to run the motor straight away, but the P28 is a good option if you want to chip the ECU so it can run Crome, Neptune, Hondata etc. If your motor is an OBD2 motor then you'll see the code PDE stamped on your head above the exhaust ports - the ECU will also be a PDE (if you got one with the motor). The PDE is basically the same as a P13 except its OBD2 and the tuning is a little more aggressive

h23jdmlude

my head has p13 stamped on the head above the header, so would that mean i have an obd1 motor then? also would i need a chipped ecu with the mods i have, i have cai, header, 2.5'' apexi catback, high flow cat, vafc II, light weight fly wheel, and a stage 2 clutch. i should be able to run a p13 ecu with just that right? and if im right i wont need a chipped ecu untill i do things like cams, valve springs, valves, intake manifold, and the throttle body. can any one correct me if im wrong and point me in the right direction

Seismic

Yes, P13 head means OBD1 motor. Incidentally, I don't know what it's like in the States but in Australia it is illegal to put a motor in your car that is older than the chassis without an engineer's compliance certificate.
To answer your other question let me first clarify what the ECU does. Among other things, it takes measurements of the absolute air pressure in the intake manifold, position of the throttle butterfly, rpm, crank position, vehicle speed and O2 present in the exhaust and combines this information to make a decision about how much fuel to inject into the cylinders given the current conditions.
Your VAFC2 intercepts several of these sensor signals and modifies their values to "trick" your ECU into adding or subtracting fuel depending on how the VAFC2 is programmed.
So for a start, I would remove the VAFC2 and let the H23A run with a P13 (or whatever you end up with) just to get it running on a "factory" tune. The P13 will cope with all your mods but without the flexibility of squeezing more from them. This is where your VAFC comes in - but get the engine running without the VAFC first. You will need to do a proper tune when you re-introduce the VAFC to the car.
A piggyback system requiring a chipped ECU would be the next level of ECU upgrade from your VAFC. It allows the ECU to make its own decisions based on real (not manipulated) sensor data. Up from there you have standalone ECUs such as Haltech, Autronic, AEM EMS, Motec etc etc.
WHat you end up with will depend on where you're heading with the car. Are you thinking forced induction or all motor? How aggressive are your cams going to be etc?
On that point, note that upgrading your valves will not give you any more performance. They are just a necessary upgrade to handle the more agressive lift from your cams. If you don't upgrade the valves and springs you will not be allowing the cams to free up as much horsepower as they are designed to do - does that make sense?
My suggestion to you if you are looking at spending the kind of money involved in aftermarket cams and valvetrain is to consider a chipped ECU with Hondata or equivalent at the very least.
Also, if you do plan to go forced induction at some point down the track don't waste money on cams for an N/A setup. VTEC cams are designed to utilise the extended opening durations to create an overlap whereby the exhaust gas velocity assists the inflow of intake air into the cylinders at the top of the induction stroke. A more aggressive N/A cam will extend this even further - but the moment you slap a turbo on it, all your precious boost will shoot straight through the combustion chamber until the exhaust valve closes. In this case, a cam profile developed for turbo applications that limits the overlap but keeps the lift is what you'd be after.
All that said, a stock ECU (with or without the VAFC) will still turn the engine over with all of these mods - you just won't be getting the full benefit of the mods. What's the point of spending all that money if you skimp on the ECU?
End braindump ... Hope that helps 8-)

lithiumus

Thought I would post up some info / re-confirm some things, etc. I've posted a lot on hondaswap.com but it was like crickets over there and at the time no one could help or was willing to help... that was back in 2006 when I got my swap done.

It was a daily driver so I just needed it to be reliable and pass emissions OBD2. The engine went into a 99 Accord Coupe so it was generally a pretty good match.

- All H series JDM engines that were 97+ all did not have crank sensors located at the oil pump
- All H series JDM engines that came in Accords all had electronically controlled EGRs and 3 wire IACV
- All H series JDM engines that came in Preludes all had vacuum controlled EGRs and 2 wire IACV

CH9 = JDM FWD Accord SiR
CL2 = JDM AWD Accord SiR
CL1 = JDM Euro Accord Type R
CH1 = EDM Accord Type R

Both the CH9 and CL2 had H23A engines using the PCF ECU
The JDM Euro Accord Type R is the CL1 and had an H22A engine using the PCD ECU
The EDM Accord Type R is the CH1 and had an H22A7 engine using the PDE ECU

The EDM engine has the crank sensor located at the oil pump. The EDM OBD2B pin outs are slightly different and will through a code until you correct the pin outs. I believe it's an O2 sensor wire / heater that is out of place as well as a few other pins.

I've tested the PCD ECUs and one of the versions may have the same pin outs as the EDM but I was only able to confirm the EDM using a service manual and haven't been able to obtain a JDM service manual.

The JDM ECUs will work nicely in an OBD2B base car like the 98+ Accords but you need to move the Fuel Pump pin over (aparantely a known mod for using JDM ECUs).

The PCF ECU will work but if you want to be able to drive normally, you will need to retro-fit the last connector which is used for Autos only. You'll need to send the correct voltages to the correct pins to tell the ECU that you are in "D" drive and not Neutral or Park. Best thing to do is use a 2-way relay and hook it up to your parking brake... i.e. when the parking brake is up, the ECU should see either P or N and when the parking brake is down, the ECU should see D.

Hope this helps answer some of the questions. I currently am using an AEM EMS which I have setup to also pass emissions (with flying colors BTW) but I think I'd rather run the PCF or PCD ECUs so that's it's more OEM and hassle free.

I'm also not 100% sure which pin controls the IAB but I'll figure that out with a multimeter...

If you try to run an OBD2B ECU that expects to see a crank sensor at the oil pump like the PDE ECU or PAA ECU (USDM F23A1) it will throw a random misfire code (even though it's not random misfiring). An OBD1 ECU will work fine but without the EGR working, you'll never pass emissions. If you want to use a Prelude OBD1 ECU that can control the EGR, you'll need to swap in a vacuum controlled EGR to mate with it.

A Blue Lude

That's a good post.

Unfortunately Preludes would have a harder time using the various Accord ECUs since the Prelude used the simpler hardware and were at best OBD2A. A US OBD2A ECU that expects the crank sensors on the oil pump will also throw misfire codes, although how bad that is can vary, it seems.

Are you using AEM to make EGR work for Drive Clean or are you not? What sort of converter?

lithiumus

The problem with the Random Cylinder Misfire codes is that it causes the ECU to go into Limp mode or at a minimum dump fuel. I tried more than 3 times to pass emissions but as soon as the check engine light comes on (random misfire) when holding the RPM, it starts to dump fuel for safety and you end up failing the emissions big time. I even tried resetting it during the test but it's too late and too much fuel being dumped.

Yes, I'm using the AEM to activate the EGR. I use the custom map which allows me to vary the EGR duty depending on the RPM. I basically set a high enough EGR duty +- 1,000rpm around where the Drive Clean test is held. Then I adjust the fuel maps around those cells and reduce the fuel. I paid to have the car sit on the emissions tester for an hour and on the dyno so I could tune it. It's a fine balance, if the fuel is too lean, HC and CO look fantastic but the NO (Nitrogen) goes sky high. You combat that with more EGR duty but that richens up the mixture and increases HC and CO. I had to play around with it for the entire hour and finally got it right. For idle, you don't have to worry about NO so I just set the idle to be nice and lean for the test (14.9 - 15.1). You don't want to drive around with such a lean idle and the car likes to stall...

I also converted the JDM Internal Coil to a 97+ USDM Prelude external coil which improved starting significantly with the AEM. I had no troubles starting the car using the JDM, EDM or USDM ECUs but the AEM was more finicky.

My swap wasn't the best and they did take some shortcuts... My header is the JDM 4-2-1 that had a 2.5" collector but they chopped it and welded it directly to my 2.25" OEM Cat converter. At some point, I'll have this all re-done but since it's just a daily driver, I don't want to spend any more money than I need to... I've got the Accord V6 exhaust that I was considering mating. I've got the V6 collector which I believe is also 2.5" so I could repair the JDM one and have it properly hooked up to the V6 cat and piping...

A Blue Lude

That's interesting - I didn't notice (on the OBD2A Prelude ECU) anything unusual happening while it is throwing a flashing misfire light. I forget if the solid CEL after a few driving cycles did anything...but I think the thing stayed in closed loop and all that, working merrily away. Never got to run the PCD ECU for obvious reasons, sadly.

Also converted the JDM distributor to external coil.

I knew a guy with a Prelude who was talking about messing around with AEM and EGR, my much more ghetto EMS is not going to be up to the task, I imagine.

Next Drive Clean will be an adventure, could always just do another conditional pass. I'm hard on my converters before I take anything else into account

Rosko

iTrader: (1)

Your idle air/fuel doesnt sound too bad at all, if it stalls off idle its probably the acceleration fuel settings. Those can be very difficult to get nailed down and I have yet to get mine perfect. Its much easier to just run the mixture slightly on the rich side to compensate for the huge rush of air that comes in when you press the throttle.

As for starting the car, the AEM isnt even looking at the fuel maps, so even if you have those on par the car STILL may be hard to start. There is a small table called "crank fuel" (I'll have to double check that name) but basically when the car is in cranking mode below 300 rpm the only fuel values its reading are coming from this table. The table is setup by temperature, ie. a given temperature = XXXX pulsewidth of the fuel injector regardless of the fuel map or anything else. Once the car is started the car switches over to the main fuel map and trims such as warm up compensation and all that apply. I played around with this alot last winter and was able to get my car to fire right up (dead cold) and idle in -20 degree weather. I'm talking crank for only a second or two and it fires. If the car cranks for a long time and eventually starts then increse the values in that table for the given temperature. I had to nearly double the values in some spots to get it to start in the cold weather. Theres also a table called "start extra" which injects an extra percentage of fuel for 30 seconds I believe, and then the warm up enrichment tables keep it going from there on as well till its warmed up. If it starts and then dies look to these tables, but if it just plain cranks forever before starting then deffinately go in and add more in the "crank fuel" table.

lithiumus

Thanks man. I've been playing with those tables for 3 winters now. It fires up good but usually takes 2 tries below -10 Celcius (-4 F) I've solved most of it by increasing the Start Extra as it was firing but not catching and idling. Slight increase in Crank Pulse helps too. I'm just so sick of sitting in the car with my laptop in -20 to -30 degrees Celsius weather trying to get the daily driver to start properly. My wife is more than irritated watching me in the passenger seat. I'm going to put back an OEM ECU and be done with it.

The stalling is usually off idle when I'm in gear (usually under 1500rpm) and when I hit the clutch, it dips down below 800 and if I'm lucky it recovers, otherwise it stalls. I find that it stall more when humidity is high outside (raining, etc). I'm also sick of adjusting the idle trims. I always come close and then I stall. The power steering at full lock will usually cause a stall as well. Thanks anyway. Going back to a stock ECU that will pass Emissions and support all the OBD2B electronics is my best solution... I'll put the AEM and Wideband controller up for sale if I can get the JDM ECU working and pass emissions.

lithiumus

The only reason I know is because I was able to put the car on the Dyno and hook up the emissions sensor in "testing" mode and basically watched the HC CO NOX AFR in realtime. Everything looked great and as soon as the CEL came on the HC and CO went through the roof in an instant and AFR dropped close to 12. Even when I reset the CEL in real-time, that immediate spike was enough to cause the Drive Clean to fail.

If I understand correctly, to be able to pass emissions, you really need to be in Open loop i.e. allow the O2 sensors to vary the AFR. In closed loop, the maps are likely not set ideally for 14.7 AFR to pass emissions... but hey, I can't confirm that 100% because the ECU will always go into Open loop at those cruising speeds and dyno loads.

Do you still have your PCD ECU? What are the last 3 digits if you still have it. I have 2 PCD ECUs. One is 004 and the other is 014. Let me know. I wonder how will the PCD ECU will run the H23A? My plan is to use the PCF and create a harness to mimic the Auto shifter.

A Blue Lude

I run a wideband permanently installed in the car - maybe I should go back and check again because that summer the sensor was on the way out. But I remember wondering how it affected the engine, if at all. It seemed to still stay in closed loop...

My car can run a drive clean cycle without tripping it, but I got worse emissions than with the P28 (not by much)

Closed loop is when the oxygen sensor is used to trim fuel to around 14.7. Open loop is when fuel is straight off the table values, and at every load point I've seen it's richer than stoichometric (on stockish engines, of course).


edit: ideally I'd just drop the car as low as possible, put a lip on it, and just do an idle test which would be super easy to pass

ESP.net

I called Japanese Star in Albany NY today for another H23A Vtec Blue Top, they have 7 of them... 4 of them are stamped PDE so specify you want a PDE one and they will get you covered. PDE nice surprise is the better performance valve angle and possibly type s/ euro r cams Got a feeling I need to make a buck of this ~John

A Blue Lude

I don't get what's special about this PDE stuff. Has anyone actually measured the head itself? Plenty of late model H22A4s have "PDE" as well. Precord96's measurements suggested that the primaries on the H23 are different from the H22, I thought - which would make the H23 cams different from the H22, which would be no surprise if true.

ESP.net

All I can say is with my H23AVtec PDE Blue Top, PDE, is same head that is on Type S/Euro R, Some H22A4 heads have been said to be PDE but not all, from that I am aware of.

PDE has a different valve angle little better for flow/performance. Cams that were in the PDE head I got have blue tint, which is the magnesium coating which is to the Type S and Euro R from what I have read.

The different valve angle Euro R/Type S PDE has had some issues with Euro R/Type S cams in a regular P13 H22 head (rocker wear) from what I have read.

Natalie from BT, also has some experience with the H23AVtec Blue Top she also agreed she has gotten a H23AVtec Blue Top before with PDE head which she said also to have the Euro R/Type S cams.

All (4) of the PDE H23AVtec Blue Tops from japanese star all appear to be automatic with auto fly as per phone conversations I had

Rosko

iTrader: (1)

My Bluetop happened to have a P13 head

As far as I knew no usdm head had PDE stamped on it. The intake manifold side is completely different as it has the "air injection" ports built into the head where the intake manifold mounts, which also takes a different gasket than the usdm H22's.


Heres a link with pics.
https://honda-tech.com/forums/honda-prelude-4/euro-r-pde-vs-stock-p13-cylinder-head-comparison-pics-1995637/


EDIT: Hey Blue I see you posted in that thread.. do you in fact have a PDE head that differs from the Euro-R head?

vinuneuro

The current cylinder head parts codes change depending on the year:

97 Base- P5M
97 SH- P13
98-00 All- PCF

PCF is the EuroR designation isn't it?

A Blue Lude

PCD is Euro-R.

I can look at my H22A4 head (PDE), but I'm not sure what I'd be looking for. I know of another with a H22A4 and a PDE head. My cams were not blue...afaik.

lithiumus

PCF is the Accord SiR Wagon with H23A designation
PCD is is the JDM Euro-R
PDE is the EDM Type R H22A7

At least from an ECU perspective...

A Blue Lude

It will say it on the big sticker on the side of the timing cover as well...

lithiumus

I was wondering if anyone has a copy of or access to the JDM Service Manuals for either the PCF Accord SiR H23A wagon or PCD JDM Euro Accord R?

mooze

hey been have read this thread and have nothing about my head. its stamped p13-2 everything says p13-2 not z or 1 or whatever else. just p13-2. i think even the cam gears have it

lithiumus

The code on my timing cover sticker is PCF. My engine came off of a 2001 Accord SiR Wagon with AWD.