Swapping JDM H22a into my JDM F22b 4th gen Prelude
05-10-2018, 11:31 AM
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Swapping JDM H22a into my JDM F22b 4th gen Prelude
I bought two 4th gen preludes between last year and now, One with a JDM H22a for parts ( was not driving but had almost everything, and what the engine didn't have i bought and rebuilt the engine ). The Prelude with the JDM F22b came driving but the engine was miss-firing. I want to swap the H22a into the F22b prelude. I thought it was a straight swap but in forums I am reading that the wiring harness is not the same.
The JDM h22a engine harness was unplugged by the firewall, will it plug directly into the firewall plug of the JDM F22b Prelude harness? and IF it does will all the wires be in the correct conectors?
Would the Vtech still need to be wired independently IF the H22a engine bay Harness plugs into the F22b firewall plug ( It woul make it very easy if, from firewall to ECU jack the harnesses are the same ie. wires already there for the vtech and knock sensor if the JDM F22b doesnt have one. )
The H22a does not have a crank position sensor as for the F22b I'm not sure yet but if they are similar in that sense ( both not having it ) does it make the wiring easier?
Is there anything esle about this swap that may not directly work. I've read that the exhaust piping might be different but i can just use the one that came with the JDM H22a prelude if necessary.
Any help would be greatly Appreciated, Ive always wanted to restore a Lude. And all Mechanical work is DIY
The JDM h22a engine harness was unplugged by the firewall, will it plug directly into the firewall plug of the JDM F22b Prelude harness? and IF it does will all the wires be in the correct conectors?
Would the Vtech still need to be wired independently IF the H22a engine bay Harness plugs into the F22b firewall plug ( It woul make it very easy if, from firewall to ECU jack the harnesses are the same ie. wires already there for the vtech and knock sensor if the JDM F22b doesnt have one. )
The H22a does not have a crank position sensor as for the F22b I'm not sure yet but if they are similar in that sense ( both not having it ) does it make the wiring easier?
Is there anything esle about this swap that may not directly work. I've read that the exhaust piping might be different but i can just use the one that came with the JDM H22a prelude if necessary.
Any help would be greatly Appreciated, Ive always wanted to restore a Lude. And all Mechanical work is DIY
05-10-2018, 11:43 AM
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Re: Swapping JDM H22a into my JDM F22b 4th gen Prelude
Forgot to Specify that the JDM F22b is DOHC not sure if that helps or if it is obvious.
But Please i need assistance because i would like to minimize downtime.
But Please i need assistance because i would like to minimize downtime.
05-11-2018, 10:38 PM
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Re: Swapping JDM H22a into my JDM F22b 4th gen Prelude
I bought two 4th gen preludes between last year and now, One with a JDM H22a for parts ( was not driving but had almost everything, and what the engine didn't have i bought and rebuilt the engine ). The Prelude with the JDM F22b came driving but the engine was miss-firing. I want to swap the H22a into the F22b prelude. I thought it was a straight swap but in forums I am reading that the wiring harness is not the same.
The JDM h22a engine harness was unplugged by the firewall, will it plug directly into the firewall plug of the JDM F22b Prelude harness? and IF it does will all the wires be in the correct conectors?
Would the Vtech still need to be wired independently IF the H22a engine bay Harness plugs into the F22b firewall plug ( It woul make it very easy if, from firewall to ECU jack the harnesses are the same ie. wires already there for the vtech and knock sensor if the JDM F22b doesnt have one. )
The H22a does not have a crank position sensor as for the F22b I'm not sure yet but if they are similar in that sense ( both not having it ) does it make the wiring easier?
Is there anything esle about this swap that may not directly work. I've read that the exhaust piping might be different but i can just use the one that came with the JDM H22a prelude if necessary.
Any help would be greatly Appreciated, Ive always wanted to restore a Lude. And all Mechanical work is DIY
The JDM h22a engine harness was unplugged by the firewall, will it plug directly into the firewall plug of the JDM F22b Prelude harness? and IF it does will all the wires be in the correct conectors?
Would the Vtech still need to be wired independently IF the H22a engine bay Harness plugs into the F22b firewall plug ( It woul make it very easy if, from firewall to ECU jack the harnesses are the same ie. wires already there for the vtech and knock sensor if the JDM F22b doesnt have one. )
The H22a does not have a crank position sensor as for the F22b I'm not sure yet but if they are similar in that sense ( both not having it ) does it make the wiring easier?
Is there anything esle about this swap that may not directly work. I've read that the exhaust piping might be different but i can just use the one that came with the JDM H22a prelude if necessary.
Any help would be greatly Appreciated, Ive always wanted to restore a Lude. And all Mechanical work is DIY
I believe I get what you are asking,
The body harness will work for any motor you want to use, but if the car wasnt vtec from the factory. You will need to run a wire from under the hood to the ecu, adding a pin in the pigtail where its missing on the non-vtec body harness. Assuming you swapped over the h22 ecu too. Same will go for the knock sensor, if you are running a stock ecu. If I recall right only "obd2" f series had knock sensors, so unless it was a stock vtec lude, your in the same boat running a wire as with vtec.
The h22 does have crank sensors... obd1 uses the distributor, same as pretty much all year jdm engines. USDM Obd2 h22's have one in the distributor and one in the oil pump. If you are obd1, all you need is your distributor.
As for exhaust, as long as the cat-back is all stock/stock location. All you will need to do is keep the exhaust manifold and downpipe from the original h22a lude. The manifold flanges are different between F and H series. But going from 4th gen to 4th gen isnt going to give you issues, or at least shouldnt.
05-15-2018, 09:28 AM
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Re: Swapping JDM H22a into my JDM F22b 4th gen Prelude
I believe I get what you are asking,
The body harness will work for any motor you want to use, but if the car wasnt vtec from the factory. You will need to run a wire from under the hood to the ecu, adding a pin in the pigtail where its missing on the non-vtec body harness. Assuming you swapped over the h22 ecu too. Same will go for the knock sensor, if you are running a stock ecu. If I recall right only "obd2" f series had knock sensors, so unless it was a stock vtec lude, your in the same boat running a wire as with vtec.
The h22 does have crank sensors... obd1 uses the distributor, same as pretty much all year jdm engines. USDM Obd2 h22's have one in the distributor and one in the oil pump. If you are obd1, all you need is your distributor.
As for exhaust, as long as the cat-back is all stock/stock location. All you will need to do is keep the exhaust manifold and downpipe from the original h22a lude. The manifold flanges are different between F and H series. But going from 4th gen to 4th gen isnt going to give you issues, or at least shouldnt.
The body harness will work for any motor you want to use, but if the car wasnt vtec from the factory. You will need to run a wire from under the hood to the ecu, adding a pin in the pigtail where its missing on the non-vtec body harness. Assuming you swapped over the h22 ecu too. Same will go for the knock sensor, if you are running a stock ecu. If I recall right only "obd2" f series had knock sensors, so unless it was a stock vtec lude, your in the same boat running a wire as with vtec.
The h22 does have crank sensors... obd1 uses the distributor, same as pretty much all year jdm engines. USDM Obd2 h22's have one in the distributor and one in the oil pump. If you are obd1, all you need is your distributor.
As for exhaust, as long as the cat-back is all stock/stock location. All you will need to do is keep the exhaust manifold and downpipe from the original h22a lude. The manifold flanges are different between F and H series. But going from 4th gen to 4th gen isnt going to give you issues, or at least shouldnt.
whilst working on my car i noticed between the Japanese writing on the underside of the hood it says "H22a" so assumin this is the hood that originally came with the car, i should have no wires to run because it should have provisions for everything pertaining to that engine.
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