dsl77

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Hello,

I just installed my h2b in my 98ek. it is a jdm h23a vtec. right after firing up, i got 3 cel: 8, 14, 22. I fixed 22(vtec pressure switch)by bypassing at the ecu. however, i was hoping to get some help or insight with the other 2. car started up first try, but the idle is fluctuating up and down probably due to the cel 14.

this is what i have so far: p72 obd1 with h22 map and conversion harness, complete '99 jdm h23a vtec. if you need more info, please ask.

cel 8: tdc sensor. the dizzy it came with was internal coil with all sensors within it. i rewired to work with the obd1 ecu and connected all wiring to the dizzy. i don't even know where to start with this one...

cel 14: iacv. The one on the intake manifold it came with is a 3 wire. I switched pin a14 to a12, then connected a13 to a23 on the obd1 side. I can't seem to get the cel to go away, nor is it even working. is it even possible to run the 3 wire iacv with the obd1 ecu??? or do i need to get the adapter plate and install the 2 wire?

I've been searching all over, but not getting any definitive answers. any help would be greatly appreciated.

1991_crxsi

iTrader: (1)

CEL 14: It is impossible to use the 3 wire IACV with the OBD1 ECU without getting a code unless you delete it completely in the tune. In other words, there is not a wiring fix that allows you to run the H22 OBD2 IACV, instead you must either delete it with yout tuning software, or just use an OBD1 2 wire. You either need to swap the entire manifold, swap the upper portion, or use an adapter plate.

CEL 8: the OBD2 H23a internal coil dizzy should be replaced with an OBD1 H22 dizzy (either internal or external). There was a thread where a guy tried to use one and got all kinds of advice and diagrams, but it never worked right. They do not send the signals in the same way the the B series OBD2 does so that wiring solution will not work. If by some chance someone out there knows how to use the stock H23A OBD2 internal coil dizzy with a P28/P06/P72 then please chime in with a diagram/instructions/link. From my experience, you are going to have to switch to the OBD1 distributor.

dsl77

iTrader: (1)

thanks for the reply..

on cel 14: all the stuff online is very vague whether the 3 wire iavc would work with the obd1. most say it will, but I guess it means you can use the wiring, but with the 2 wire iacv only. Unless someone here knows better?

on cel 8: damn, i just tossed a obd1 dizzy. when i opened it up, they looked almost identical, guess its just cosmetically identical.

dsl77

iTrader: (1)

14: just installed a spare obd1 iacv, got rid of the cel. just need to get the adapter plate.

8: anyone got a spare obd1 dizzy?

thanks

dsl77

iTrader: (1)

Ok..... bought a usdm obd1 h22 dizzy td60u. Plugged it in. Reset ecu. Started it. Cel light turns on. Still having the problem. I traced continuity of the wires all the way to inside the ecu and it was ok. Amy other ideas? I have a obd1 p72 obd1 ecu chipped for h22. Please help, feeling defeated. Thanks for you help in advance

dsl77

iTrader: (1)

I'm thinking it might even be my ecu? does anyone have an obd1 p72 i can try or a car i can plug my ecu into?

1991_crxsi

iTrader: (1)

It sounds like something is incorrectly wired.

dsl77

iTrader: (1)

From dizzy(td60u):
tdc-p = orange/blue , but looks more like peach color. I traced that all the way to ecu at pin 13 on p72 obd1.
tdc-m = white/blue. I traced that all the way to pin 14 on obd1 p72.
*using the obd1 pinout chart on ff-squad's page

I have no other codes, but this one is keeping me in limp mode. Did I miss something here? One time I got it to start and idle for 15 seconds without cel, when I revved it, the light Turned on.

I'm in LA. Is there anyone with a spare ecu that I can try? Or a car I can plug my ecu up to? Any insight or help is much appreciated. Thanks for even taking the time to look at thIs post. If you guys want anything, like pictures of anything, let me know. I know everyone loves to see a pic. Lol.

2fast4u831

Do you know if the IACV is good? in the throttle body there are 2 holes. 1 goes to the iacv and the other to the fast idle. try plugging the one that goes to the iacv( I think it's the top one) to see if it helps with idle. if it does help your iacv might be bad. good luck man.

2fast4u831

Is it throwing a code? if so what code is it?

dsl77

iTrader: (1)

@2fast. Iacv is good. Idle is good. except throwing cel 8. TDC sensor.

EddyNN

Check the resistance on those TDC wires, could be a bad connection. Sometimes when you check for continuity, everything seems fine so you figure it should work. But then you start the engine and the vibrations break the circuit for fractions of a second and it throws the code. Check the pins on the ecu, and also on the dizzy harness.

I had a similar issue on my civic, same sensor, what caused it was the pins on the ecu plug not going in all the way. I had wrapped and soldered the wires on the pins after the old wires split where they go into the pin, so the pins jammed in the plug before bottoming out. Ended up fixing my messy repair and all is well.

If you check the wires/pins and find that they are fine, then your TDC sensor is bad.

dsl77

iTrader: (1)

@EddyyNN, thanks for responding. I already figured what was wrong... when checking continuity it was fine, but somehow there's a short on that one wire. I just happened to check continuity of all the pins to ground, and just that one wire going to the tdc sensor was shorting. I am going to put the jdm dizzy back in to see if it will work. my hunch is that it will.

As for the rest of the issues:

1. i cant seem to idle with this jdm h23vtec throttle body. i went to adjust the idle screw, but it doesn't have one. its the same one as the S2000 tb. I think I am going to take it to the machine shop and have the threads and port just machined in so that i can install an idle screw.

2. the h2b header from PLM is awful in fitment. the flange hangs way too low. Its 2 inches from the ground. I contacted them and they told me to put the collector flange where i want it, then tighten the manifold flange stud nuts. basically bending it with the force of tightening the nuts. with my car on jack stands, i jacked up the collector flange to where i wanted it, but it just sprang back. i just got some metal to make a bracket with. should be ready next week sometime.

3. no more cel, but the iab doesn't work. it holds vacuum, but the solenoid won't release the pressure to open the valves. for now, i just capped it and took out the vacuum hose to keep the valves in the open position. definitely more torque down low with the valves closed. i am not getting rid of it because its my daily driver.

Update: obd1 ecu switches ground signal, so had to supply with 12volt power, it now works.

again, thanks to all that gave me valuable input... There is so much misinformation out there that searching did not help me out with this particular motor.

dsl77

iTrader: (1)

Update:
put the dizzy that came with the motor back in. the jdm dizzy works fine. If it doesn't work, you screwed up the wiring somehow.

I haven't had a chance to machine a new idle screw yet, but will keep this updated until I iron out all the kinks to my swap.

1991_crxsi

iTrader: (1)

For clarification: Does that means that the OBD2 Dizzy can wired to work properly with the OBD1 ECU? Thanks.

dsl77

iTrader: (1)

The jdm obd2 dizzy seems identical to the obd1 except for the rpm wire. However, you can just add that 1 wire.
I am running an obd1 p72 with a jdm obd2 dizzy. No cel since I found that short.

1991_crxsi

iTrader: (1)

Thanks.

Dorkenheimer

You sure PLM didn't send you a straight H header?

I got done tracking down CEL's a few weeks ago. I feel your frustration. After I was done, I realized how important it was to check all the wiring like 90 times, with a buddy, to make sure things were right. I spent a week tracking down one CEL only to find out it was indeed a switched wire. Keep at it!

Dorkenheimer

Does this help at all?

https://honda-tech.com/honda-prelude...butor-2275163/

dsl77

iTrader: (1)

@dorkenheimer. I cleared all the cels already. Not 100%sure, but if they were regular headers, the collector would be too high, right? As for the distributor, as I said above, the jdm obd2 seems like a direct replacement for an usdm obd1dizzy after adding the rpm wire and repinning the plug.

I'm just trying to find time to get the idle screw machined in and weld new brackets to my headers to hold the collector up.



Thanks for posting

dsl77

iTrader: (1)

Finally machined the ports and threads and added an idle screw to my throttle body. works great. You can also see my map sensor remote mount adapter that i made for hood clearance.



backside(note: 625. its the size of the throttle plate. as for gasket, i used the usdm type r gasket)