Prelude questions

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wiredjosh

Member
Hey all,

I am helping a friend with an F22 to H22 swap in his 4th gen prelude. I have looked everywhere and can't seem to find any info on doing this swap, or anyone who has done it. I know that some wiring will need to be changed to accomodate the alternator, but I don't know if there is anything else that needs done. Also, I have heard some talk about removing the belt from the balancer shafts to save rotational inertia. Is there any good reason to do this? Can the belt be reliably removed without removing the shafts too?

Finally, are there any tips in general to doing this swap? Has anyone out there done this lately? If you can help I bow down to you! :worthy: :worthy:
 
That swap would be the same as swapping an F22 to H22 in an accord. It's not that hard. Do a search, click on my sig, and ask some more specific questions.

You will want:

The right header +downpipe
Powersteering hose, if you can't use the stocker.
P13 ECU
Maybe a different tranny

Wire up four wires.

I wouldn't disable the balancing shafts unless this is going to be a racer. Those shafts counteract vibration in your motor. Your engine would vibrate a lot, and wouldn't last as long if you disable them.
 
ok, here's what we're doing. He's ditching his AC and PS cuz the AC doesn't work and he doesn't want the ps hooked up, so that's no big deal. He is going super cheap on the swap, and just bought a motor, and we're keeping the F22 trans/clutch/flywheel. He's also keeping the f22 ecu for now, and he picked up a VAFC for the vtec. He has a DC sports 4/2/1 header going into an N1 knockoff catback.

I guess I don't understand your sig very well Tab, cuz I don't get what 4 wires need run. I assume one is a knock sensor. I'm just not familiar enuf with the H motors to know what needs done. I need you to lay it on the line for me. I must be a dunce cuz I have done a bunch of searches and I just get nothin helpful. :blink:

I also need to know how to check codes on the car once we get it in. I am a CRX guy by trade, and have always had the self-diag lite to cheat off!

Thanks!
 
The four wires you need to run are VTEC solenoid (see below), VTEC pressure switch (see below), IAB (intake air bypass, or the intake manifold butterflies, see below), and knock sensor (see below). You'll also need to lengthen a couple wires, but those become pretty evident when the wiring harness won't plug up. :)

The problems here are, the F22 ECU won't be looking for the VTEC stuff, IAB or knock sensor. The knock sensor isn't a huge deal, but it's a nice safety feature, especially if you get any bad gas. Also, with the IAB's closed all the time, your friend will be missing out on some top end power, as the shorter intake runners won't open. You can remove the IAB assembly from the intake manifold, but I'm not sure if it's as easy as just pulling them out and reassembling the manifold.

Of course, the major problem is that the stock F22 ECU won't be able to engage VTEC. This make the H22 swap worthless. Your friend should really spend the extra $150 to get a P13 ECU.
 
Yeah, I know about the F22 ecu not running VTEC, and that's why he bought the VAFC. I forgot about the dual runner intake manifold, so I'll have to kick his butt some about that. It makes good sense now, and I appreciate the help. Also, I was working on getting some of the old wiring harness/hoses/crap off the new motor, and I noticed that there is a black plastic canister type box directly under the intake mani, and it's broken. I'll post up a pic of it in a bit. Do you guys know what it does, and if I need to repair or replace it? It looked like there were some vac lines coming and going from it, so maybe it has something to do with the dual runners?
 
the vafc works with the stock computer to engage the vtec at the desired rpm. If the ecu knows nothing about vtec, then the vafc cannot magically engage it.
Get the p13
 
Originally posted by wiredjosh@Jun 30 2004, 06:19 PM
Yeah, I know about the F22 ecu not running VTEC, and that's why he bought the VAFC. I forgot about the dual runner intake manifold, so I'll have to kick his butt some about that. It makes good sense now, and I appreciate the help. Also, I was working on getting some of the old wiring harness/hoses/crap off the new motor, and I noticed that there is a black plastic canister type box directly under the intake mani, and it's broken. I'll post up a pic of it in a bit. Do you guys know what it does, and if I need to repair or replace it? It looked like there were some vac lines coming and going from it, so maybe it has something to do with the dual runners?
Click to expand...

you definitely want the P13, plan on it.

The black cannister connects to the IAB. You can bypass the cannister and run from the intake manifold to the IAB directly.

Layin it on the line:

VTEC Pressure sensor, under the oil filter
Solenoid is next to the distributor
Knock sensor is above the oil filter.
IAB is connected to the mentioned black box.

It will be almost as cheap to buy an Ebay header as to find a JDM downpipe, if yours is missing. Plus, the aftermarket header and downpipe don't require any welding, and have a location for your O2 sensor(down below). The IAB won't throw a code if you don't wire it. Running without power steering, I've heard, can damage the rack, and there is a sensor on the hose for something. You'll have to lengthen a lot of wires, but you'll keep all of your OE vacuum setup. Switch the EGR over, and your front water neck, to save on wiring. Also, your old harness will have a yellow wire with a red stripe going to the oil pressure sender on the back of your block, above the oil filter. Your new VTEC pressure sensor will be below the oil filter. I have found these two wires to be the same, as far as reading oil pressure. I ran the oil pressure wire to the VTEC sensor, and the oil pressure reads fine.

Tips in General:

Give yourself plenty of time. Pull the engine and tranny as a unit, and rewire your harness with easy access. If you can't decide what to do next, grab a wrench and do SOMETHING, since downtime kills the clock. Drop your crossmembers out of the way completely, because they will hinder the new motor's entrance. Leave the crank pulley off while dropping in new motor. Leave the driver's side, and tranny mount loose until the rear mount is bolted down. Once every side is loosely mounted, torque it all down.
 
Originally posted by driverunknown@Jun 30 2004, 07:01 PM
If the ecu knows nothing about vtec, then the vafc cannot magically engage it.
Click to expand...

I'd have to disagree with you on this. I've installed many a VAFC in crx's with D16vtec swaps that ran the stock crx Si ECU, which obviously has no inkling about vtec. I'm gonna tell him to pony up for the ECU tho for sure. I'd hate to see him not take full advantage of this beautiful motor!!

Tab, you are definitely the man! Thanks for the help! I've done lots of civic and crx swaps, but this is my maiden voyage on the prelude/accord end of the spectrum, so your info is greatly appreciated! When you say drop away the crossmembers completely, do you mean the radius arms that go from the front member out to the suspension, or do you mean to actually drop the front crossmember?
 
Originally posted by wiredjosh+Jun 30 2004, 09:47 PM-->
wiredjosh @ Jun 30 2004 said:
driverunknown
Click to expand...
wiredjosh @ Jun 30 2004 said:
@Jun 30 2004, 07:01 PM
If the ecu knows nothing about vtec, then the vafc cannot magically engage it.
Click to expand...

I'd have to disagree with you on this. I've installed many a VAFC in crx's with D16vtec swaps that ran the stock crx Si ECU, which obviously has no inkling about vtec. I'm gonna tell him to pony up for the ECU tho for sure. I'd hate to see him not take full advantage of this beautiful motor!!

Tab, you are definitely the man! Thanks for the help! I've done lots of civic and crx swaps, but this is my maiden voyage on the prelude/accord end of the spectrum, so your info is greatly appreciated! When you say drop away the crossmembers completely, do you mean the radius arms that go from the front member out to the suspension, or do you mean to actually drop the front crossmember?
Click to expand...

there is a thrust mount that holds the front of your motor steady. The crossmember that holds that mount can be dropped easily. First, the crossmember that runs lengthwise, along side the exhaust, drop it. Then, unbolt the dogbone mount from the engine, and the two long bolts on each side of the car that hold that piece up. After that, you will notice the crossmember sagging towards the front of the car. It's loose, but still in the way, kinda. I like to remove the remaining bolts and get it out of the way, since using the creeper to get around it is a pain. Two more bolts on each side connecting to your suspension, and it's dropped.

Here's a tip. Get your radiator, battery box, and accessories out of the way. Then, loosen your suspension(and steering), and pull your axles. After that, you'll have easier access to all the stuff above. Even better, once all that is done^^^^^^, you have easier access to your exhaust, tranny, powersteering hose/rack,etc.

I don't rush anything. I'm sure there are faster swappers on this board. But I don't get frustrated very much. I just keep pulling shit apart, and putting it back together. I just did my fifth Accord motor swap a month ago. :) My dad thought I was nuts, since I didn't bother to label any bolts, wires, clips, nothing. I've done it so many times, it's like clockwork. This is why I giggle when I see how fast some people say they swap a motor. A virgin car, one that's never been torn apart before, can be a major pain. My car is my bitch, and has had everything broke loose and anti-seized. :lol:
 
Yeah, I hear you. I have done a dozen or so CRX/4th gen civic swaps, and I can pretty much sleep thru them and still get done pretty quick. This whole prelude thing has got me a little sketchy tho, there's so much more to remember and keep track. I'm gonna go back to labelling and taking pics with the digicam to keep crap straight!

So you think it's a bad idea for the guy to ditch his power steering? I can certainly leave it in, no sweat, he just said he wanted it out. I am used to cars without it, so I hafta say I don't really even know how it works! lol!
 
Originally posted by wiredjosh@Jun 30 2004, 10:57 PM
Yeah, I hear you. I have done a dozen or so CRX/4th gen civic swaps, and I can pretty much sleep thru them and still get done pretty quick. This whole prelude thing has got me a little sketchy tho, there's so much more to remember and keep track. I'm gonna go back to labelling and taking pics with the digicam to keep crap straight!

So you think it's a bad idea for the guy to ditch his power steering? I can certainly leave it in, no sweat, he just said he wanted it out. I am used to cars without it, so I hafta say I don't really even know how it works! lol!
Click to expand...

I have an Accord because I like the torque, and the extras. I have all the power options, except sunroof. If I didn't care about those options, I'd strip my car, or buy a civic. My car is also my daily driver.
 
Originally posted by wiredjosh@Jun 30 2004, 10:57 PM
I'm gonna go back to labelling and taking pics with the digicam to keep crap straight!
Click to expand...

just mark the old engine for vacuum line #'s. This way you know where they go. There are only a couple harness ends that could get messed up. If you want to mark, then just do the wires on the distributor side. I can't think of any wires in another location that could be plugged in wrong. I used a paint pen, on my first swap. There's not enough room for words, so I used a combination of dots and lines, not too fancy.

Also, if you are external coil right now, you'll need to splice one power wire to give the distributor power, since it is internal.
 
I ran my Accord without power steering after the H22 swap. It was just fine. The only thingd that kinda sucked were parallel parking and tight parking lots. Otherwise, it wasn't a hassle at all turning that 3,000-lb beast. :D
 
What do you mean mark the wires on the distributor side? Don't the connectors/wire colors match up? Now that I think about it, I think that I may have an obd2 motor. Is there a way to tell the year on the H22? Will I have to sift thru wiring diagrams and crap to figure out how to mate them up to the Accord harness, or should they plugnplay fairly easily?
 
oh yeah, and i just realized last night that the knock sensor is busted. You got any lying around, or know of a good place to get one?
 
Got mine at a junkyard for $20.

Just go and find one from a similar Accord, Prelude, whatever. It just has to be a one-wire sensor with similar thread. Bring the broken one to match up.
 
ok, so i talked tol my boy, and he's planning on getting a hondata in the next couple of weeks, so he doesn't care to spend the cash on the p13 ECU. What is the code on the F22 ECU? I need to make sure he can even get a hondata for it. Wouldn't that mean that I don't have to add knock sensor, but need the extra wires for the vtec, IABsol?

Thanks!
 
I don't remember the code on the F22 ECU. I don't think it's supported anyway, but I'm not sure.

I believe most guys get a P28 or a P72 for Hondata. The P13 isn't supported by Hondata either. One of those two ECU's doesn't require a knock sensor. VTEC and IAB will still be there.
 
I know that the P28 doesn't take a knock sensor. The P72 definitely does though. That's the GS-R ECU.

I took off the old timing belt tonight, to get the motor all ready to go in, and I'm a little confused on TDC for the front balance shaft. It has two marks on it. One is on the shaft, and one is on the face of the gear... The one on the shaft wants to line up naturally, but it's about 90 degrees off from the one on the face. Also, there's a little tube coming out from what I think is the EGR valve, and just opens into the air. I'll post a pic of it tomorrow.... do you know what I'm talking about? Is it supposed to connect to something?
 
Originally posted by wiredjosh@Jul 2 2004, 01:30 AM
I know that the P28 doesn't take a knock sensor. The P72 definitely does though. That's the GS-R ECU.

I took off the old timing belt tonight, to get the motor all ready to go in, and I'm a little confused on TDC for the front balance shaft. It has two marks on it. One is on the shaft, and one is on the face of the gear... The one on the shaft wants to line up naturally, but it's about 90 degrees off from the one on the face. Also, there's a little tube coming out from what I think is the EGR valve, and just opens into the air. I'll post a pic of it tomorrow.... do you know what I'm talking about? Is it supposed to connect to something?
Click to expand...

You can use either, but yeah, I'd use the one without knock sensor. Tuning and good gas should keep pings away anyhow.
 
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