Newbie Help needed on 96 Frankenstein Engine
Thread Starter
Junior Member
Joined: Jun 2003
Posts: 13
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From: Bangor, ME
Newbie Help needed on 96 Frankenstein Engine
Hey all...
I just bought a 96 Prelude Si in which the H23A engine has had a DOHC VTEC head put on it. Unfortunately, the conversion was done a number of owners ago, so I have limited info. Here's what I do know:
Valve cover is blue... does that mean anything? JDM maybe?
It starts, idles and runs, so the conversion was at least a partial success.
Here's the strangest part... I looked at the ECU and the part number is 37820-P0H-L51, which according to www.autoecms.com is a 96 Accord 2d Auto ??? The transmission is manual BTW.
I opened it up on the highway and the rev limiter cut in at 6500rpm.
ABS doesn't work.
Do people think the redline is being limited by the computer, or something else?
Is the ABS trouble related to the ECU issue?
Should I be thinking about getting a different ECU?
I think this thing has potential, but I'm not sure where to begin... Any help much appreciated!
I just bought a 96 Prelude Si in which the H23A engine has had a DOHC VTEC head put on it. Unfortunately, the conversion was done a number of owners ago, so I have limited info. Here's what I do know:
Valve cover is blue... does that mean anything? JDM maybe?
It starts, idles and runs, so the conversion was at least a partial success.
Here's the strangest part... I looked at the ECU and the part number is 37820-P0H-L51, which according to www.autoecms.com is a 96 Accord 2d Auto ??? The transmission is manual BTW.
I opened it up on the highway and the rev limiter cut in at 6500rpm.
ABS doesn't work.
Do people think the redline is being limited by the computer, or something else?
Is the ABS trouble related to the ECU issue?
Should I be thinking about getting a different ECU?
I think this thing has potential, but I'm not sure where to begin... Any help much appreciated!
Senior Member
Joined: May 2003
Posts: 1,052
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From: Long Island, NY
how do u know its got a vtec head on it?
how do u know the ABS doesnt work?
why didnt they just put a h22a in it?
it probably would have been cheaper
reved higher
and ill bet it would have been alot faster
what engine code are we lookin at here?...h23a1
its just below the starter on the front of the block by the rubber timing cover
what code is on the head
if its a real h22a head it should say p13 somewhere on the front
the blue cover doesnt mean shit
you can buy them a number of places
~boom
how do u know the ABS doesnt work?
why didnt they just put a h22a in it?
it probably would have been cheaper
reved higher
and ill bet it would have been alot faster
what engine code are we lookin at here?...h23a1
its just below the starter on the front of the block by the rubber timing cover
what code is on the head
if its a real h22a head it should say p13 somewhere on the front
the blue cover doesnt mean shit
you can buy them a number of places
~boom
Thread Starter
Junior Member
Joined: Jun 2003
Posts: 13
Likes: 0
From: Bangor, ME
Thanks for your responses...
Here's answers to ludeboom's Q's:
>how do u know its got a vtec head on it?
well.. it says "DOHC VTEC" on the valve cover and I thought the Si H23A engine was non-vtec.
>how do u know the ABS doesnt work?
The dash light comes on about 10 seconds after starting.. and more importantly, the wheels lock up and dig grooves into the grounds when slamming on the brakes on a gravel road.
> why didnt they just put a h22a in it?
> it probably would have been cheaper
> reved higher
>and ill bet it would have been alot faster
Good question... Who knows what the answer is though....
> what engine code are we lookin at >here?...h23a1
H23A (no 1)
> what code is on the head
P13
HF-2
Does this info help?
For iakona, do you mean the P0H ECU is a rare find? and you have a P13 available?
And if I found a P13 ECU, would it be as simple as swapping one for the other, or is it more involved than that?
Here's answers to ludeboom's Q's:
>how do u know its got a vtec head on it?
well.. it says "DOHC VTEC" on the valve cover and I thought the Si H23A engine was non-vtec.
>how do u know the ABS doesnt work?
The dash light comes on about 10 seconds after starting.. and more importantly, the wheels lock up and dig grooves into the grounds when slamming on the brakes on a gravel road.
> why didnt they just put a h22a in it?
> it probably would have been cheaper
> reved higher
>and ill bet it would have been alot faster
Good question... Who knows what the answer is though....
> what engine code are we lookin at >here?...h23a1
H23A (no 1)
> what code is on the head
P13
HF-2
Does this info help?
For iakona, do you mean the P0H ECU is a rare find? and you have a P13 available?
And if I found a P13 ECU, would it be as simple as swapping one for the other, or is it more involved than that?
Senior Member
Joined: May 2003
Posts: 1,052
Likes: 0
From: Long Island, NY
the wiring harness is identical between h23a1 and h22a/1
it appears to be an actual h23a with a h22a VTEC head on it
im not sure about the reliability of this badboy though
the p13 ecu will allow revs up to nearly 7800 rpm most of the time, and you will definitely blow the h23a1 crank if you do that
its becoming more and more clearer to me now, why you have an odd ecu, etc.
i figure that they needed an ecu with some type of vtec support but a similar redline to the h23a motor 6500 ish so thats why they didnt just use a p13
the h23a block has pretty much all the same sensors as the h22a so you could run a p13 on it without a problem, except for the whole blowing the motor thing.
as far as ABS, it sounds as tho something is not properly connected, do all the wheels do this on gravel or is it only a certain one or maybe two?
i had a loose ABS sensor on one of my wheels and it would cause the brakes to go nuts if i hit a bump, but it was easy enough for me to tighten the two 10mm bolts on the wheel hub.
i think that you can get the ABS system to give you codes, but im not sure...let me do some investigating in my helms and ill try to get back to you soon
~boom
it appears to be an actual h23a with a h22a VTEC head on it
im not sure about the reliability of this badboy though
the p13 ecu will allow revs up to nearly 7800 rpm most of the time, and you will definitely blow the h23a1 crank if you do that
its becoming more and more clearer to me now, why you have an odd ecu, etc.
i figure that they needed an ecu with some type of vtec support but a similar redline to the h23a motor 6500 ish so thats why they didnt just use a p13
the h23a block has pretty much all the same sensors as the h22a so you could run a p13 on it without a problem, except for the whole blowing the motor thing.
as far as ABS, it sounds as tho something is not properly connected, do all the wheels do this on gravel or is it only a certain one or maybe two?
i had a loose ABS sensor on one of my wheels and it would cause the brakes to go nuts if i hit a bump, but it was easy enough for me to tighten the two 10mm bolts on the wheel hub.
i think that you can get the ABS system to give you codes, but im not sure...let me do some investigating in my helms and ill try to get back to you soon
~boom
Thread Starter
Junior Member
Joined: Jun 2003
Posts: 13
Likes: 0
From: Bangor, ME
About the engine blowing up thing... that's kinda what I was afraid of...
And if there's no fix for that fundamental problem, maybe I just leave well enough alone and live with a working engine with a 6500 redline :-)
Why they did all this for such a slim vtec band I'll never know... I will admit, though, it is fun until the rev limiter kicks in.
about the ABS, I know the front two tires locked up on the gravel road... I didn't check the rear ones...
thanks again for your help
And if there's no fix for that fundamental problem, maybe I just leave well enough alone and live with a working engine with a 6500 redline :-)
Why they did all this for such a slim vtec band I'll never know... I will admit, though, it is fun until the rev limiter kicks in.
about the ABS, I know the front two tires locked up on the gravel road... I didn't check the rear ones...
thanks again for your help