How-To: JDM D15B VTEC into an EF

[Exempt]

I wrote this awhile back, just now got around to posting it...


I. Pre-swap info

Few things to note:
This how-to documents My own experiences while doing this swap into my car, a 91 CRX Si… This info should be the same or close to all the other 4th gen (88-91) Civic/CRX’s, with the main exception being mine was already multipoint fuel injection (MPFI), so I didn’t have to wire that up... If you have a DX or other DPFI car (Civic STD) you will need to wire up MPFI (some how-tos on that can be found here: http://www.angelfire.com/d20/hcivic88/dx-siwiring.html , http://www.geocities.com/teampimports/fuelinj.html , http://www.geocities.com/c_rexboy/mpfi.html) or you can buy a complete harness from rywire.com... There may also be other variations between our cars not covered here... I also used a P28 ECU, so if u use a P08, or want to use your stock PM6 ECU, then your install will be different... This how-to only covers a P28 OBD1 conversion install using the D15B engine! Though I may touch up on what’s different between the P08 and P28 since those are basically the same only less is needed to make the P08 run… This swap is pretty similar to the D16Z6 (5th gen 92-95 Civic EX/Si engine) swap into a 4th gen Civic/CRX, with a few differences... First there are a few things on the D16Z6 intake manifold, which are not on the D15B manifold, a hose for the purge control solenoid for instance... The P28 ECU looks for 2 things that may or may not be on the D15B, a 4 wire O2 sensor (most all D15B VTEC engines will come with a single wire O2), and a VTEC oil pressure switch (some D15Bs come with them, some don’t, mine unfortunately didn’t)…

I suggest you plan at least 2 weeks for the swap... I did mine myself (with greatly appreciated help from various family members, but for the most part myself) and it took me a week to finish it up... Another thing, if your engine is from a standard and you have a flywheel on the engine, take it up to be resurfaced BEFORE you begin (unless u have an 88-89, as those reportedly have a smaller surphace area and youll need to use your old flywheel with those transmissions)... I didn’t get to do this because my engine came with an automatic flex plate (obviously my engine was an auto in its previous life)... And probably the best advice I can give you, is RESEARCH! A lot of hours went into research BEFORE I bought my engine... And I still should have done more... So research! I assume that’s what your doing now by being here, so your already on the right track!



Here are some other resources that will be helpful (most are for a D16Z6/Y8, I said they were similar didn’t I?):

http://asia.vtec.net/article/d15b/

http://www.d-series.org/forums/showthread.php?t=17840

http://www.geocities.com/chacofgs/swap.html

http://www.angelfire.com/ca/DrOhm/hybrid.html

http://www.honda-tech.com/zerothread?id=1085494

http://sohchonda.com/ipw-web/bulleti...highlight=d15b

http://www.superhonda.com/forum/show...tpost&t=208335



Parts I used and an estimate of how much they cost:
Engine $615
P28 OBD1 ECU (92-95 Civic EX/Si) $130
Rywire pre-OBD to OBD1 conversion harness $190
4 Wire O2 Sensor (92-95 Civic EX/Si) $60
Clutch and pressure plate $80
NGK ZFR6J-11 spark plugs $20
NGK spark plug wires (92-95 Civic EX/Si) $60
Distributor cap and rotor $17
Megan Header $194.95
Timing belt (92-95 Civic VX)$35
Water pump (92-95 Civic VX) $55
Oil filler cap $20
MAP sensor $50
VTEC Solenoid $50 (bought it for the VTEC oil pressure switch since my engine didnt have one)

Now some parts I bought you may not have to buy, for example the Oil filler cap, my engine didnt come with one, so if yours comes with one, obviously you wont need it... You may also have to buy some extra sensors, if yours are broken... My MAP sensor was also broke, so I had to buy it... I heard you can use the stock CRX MAP, but I didn’t try it and didn’t want to mess with it...

(Note: Go here for a page to help locate and see where all the sensors are and what they are called… If yours are visually broken as most of mine were replace them! Most of them can in fact be pulled from your stock engine and reused with OBD1 without a problem, I reused my old IAT for instance…)

Here’s a list of what is required parts for this swap:
-Engine (obviously)
-P28 OBD1 ECU (92-95 Civic EX/Si)
-preOBD to OBD1 conversion harness (alternatively you can wire up the conversion yourself, it is not covered here in this write up... There’s plenty of other write ups on the subject... http://geocities.com/chipman_13/wire-conversion.html or http://www.geocities.com/kurtsi_on/page8.html just to name a few, you can also search Google http://www.google.com/search?hl=en&q...=Google+Search... For me personally that was too much trouble, so I bought this http://www.rywire.com/sitodvtec.shtml)
-4 Wire O2 Sensor (92-95 Civic EX/Si) (if u use the P28 ECU, u MUST use a 4 wire O2! If you use a P08, you can use either the 1 wire which comes with the engine, or a 4 wire O2...)
-Also required are any sensors or other things you may be missing...
For example the MAP sensor... This is usually broken on imported engines from they way the engines are stacked on the trip from Japan...

Parts that are recommended to be replaced:
-92-95 Civic EX/Si header (since your engine probably only came with the header and not the down pipe too) or preferably
an fftermarket header of some kind with the O2 sensor bung to the side (this is so you don’t have to modify the A/C condenser fan, or you could use the stock CRX Si one but its more restrictive)
-Clutch and pressure plate (for whichever tranny you plan to use, the 88s have 21 spline count, the 89s+ have 20 so make sure u get the right one!)
-NGK ZFR6J-11 spark plugs
-NGK spark plug wires (92-95 Civic EX/Si)
-Distributor cap and rotor
-Timing belt (92-95 Civic VX)
-Water pump (92-95 Civic VX)

Also don’t forget fluids and misc. things:
-Oil & filter
-Transmission Fluid (2 quarts, I used Pennzoil Synchromesh)
-Anti-freeze
-Solder (and iron if u don’t have one) or GOOD QUALITY crimps
-Electrical tape (high temp)
-Honda Bond
-Helms manuals for 92-95 Civic Si and CRX Si (or at least download them off the web)
-Engine Degreaser (to clean new engine and bay)
-Simple green (to clean new engine and bay)
-PB Blaster (you will need this to break bolts loose!)
-Anything else u can think of...

[Exempt]

II. Removing the old engine

(NOTE: This is basics only! It is taken from Helms, buy/download it for specifics and pictures!)

1. Remove the battery, starting with the negative terminal first.
2. Remove the hood. (Dont forget to disconect windsheild washer fluid tube.)
3. Drain engine oil.
4. Drain coolant.
5. Drain tranny fluid.
6. Remove intake duct and air box.
7. Remove the battery base.
8. Relieve fuel pressure by slowly loosening the service bolt on the fuel filter about one turn. (To be on the safe side, you can also remove your gas cap aswell...)
9. Disconnect engine compartment harness connectors (should be 3 of them by the under hood fuse box... I found it easier to pull them off the brackets to disconnect them, they can be a pain, but just keep working til u get them and be careful not to snap them... I used a flat head to help with the tabs...) Also disconnect the transmission ground cable found on the bracket holding the clutch cable...
10. Disconect the engine wire connectors and spark plug wires.
11. Remove the cap and bolts and then remove the distributor from the cylinder head. (I just removed the cap, but taking out the engine later on, I see why they say to remove the distributor because it was in the way of the chain hoist...)
12. Remove the throttle cable by loosening the lock and the throttle cable adjust nut, then slip the cable end out of the throttle bracket and accelerator linkage. Careful not to bend the cable!
13. Remove power steering pump. (obviously not applicable to most models)
14. Disconnect the radiator hoses and heater hoses. (There are 2 of each... The upper radiator hose is obvious, it goes from the radiator to the front of the block... The lower goes under the distributor to the thermostat... And both the 2 heater hoses come from the fire wall, one to the thermostat, the other to right under the distributor...)
15. Remove speedometer cable. Squeeze the rubber boot and pull up, but be careful not to lose the retaining clip.
16. Remove the alternator. (I didnt remove mine, I just loosened it up and remove the belt, then slid to as close to the block as I could to clear the brake master cylinder...)
17. If you have A/C, remove the A/C compressor. Loose the belt adjust bolt and the idle pullet net. Remove the compressor mount bolts, then lift the compressor out of the bracket with hoses still attached, and wire it upto the front beam. (Taking off the compressor was major pain! You have to squeeze your hands down between the radiator, and on the bottom its damn near impossible to get at... But with some time, and pateince, turning them little by little, you can get them out... Once I got the 4 bolts out I just rested the compressor on the front crossmember...)
18. Remove the shift lever torque rod, shift rod, and clutch cable. (This can be a pain aswell... Some refer to the spring pin on the shift linkage as the infamous 'bitch pin' because it can be to get it in and out... I simply took some PB Blaster, squirted the hell out of it top and bottom... Let it sit... And then took one of the long pointy A/C compressor bolts and a sledge hammer and from the bottom beat the piss out of it... Came out after about 5 min of hammering...)
19. Remove left and right drive shafts. (see section 10 in Helms) (Ill explain this later in its own section)
20. Attach a chain hoist to the engine block hoise brackets and raise the houist just enough to remove slack from the chain. (I used the hole right behind the valve cover on the driver's side, and one of the clutch cable bracket bolt holes (with a different bolt of course! Do not use bolts you need they can and will bend!)
21. Remove rear transmission mount bracket.
22. Remove the bolts from the front transmission mount. (again, can be a pain to get your arms down passed the radiator and fans... A word of advice, place a towel between your wrist and the fans, I cut the hell out of wrist loosening the top bolt on this mount...)
23. Remove the bolts from the engine side mount.
24. First remove the mount nut from under the transmission housing and remove the bolt from the side transmission mount.
25. Check the the engine and transmission if free of vacuum, fuel, and coolant hoses, and electrical wires.
26. Slowly raise the engine approx 6" and stop. Recheck for anything attached to the engine and transmission. (Good thing I did this, I forgot one of the hoses from the charcoal canister going to the back of my intake manifold.)
27. Raise the engine and transmission all the way out and it from the car. (I had someone work the hoist while I guided the engine and tranny out... Also to clear the A/C lines I had to use a load leveler to raise the engine side way up, and the tranny way down at a slant...)

Congratulations, your a little bit less than half way thru the swap!
Now you can take a break, either for the night, or just to get a bite to eat, or take a piss...

[Exempt]

III. Preparing the engine bay and engine for install


If you didnt have a flywheel on your new engine, remove the transmission from your old engine, and take off the pressure plate, clutch and flywheel, and take the flywheel up to a machine shop to be resurfaced (note: you do not really have to do this if you reusing your old clutch, but this is not reccomended!)... You may also want to take the driver's side engine mount bracket from your old engine... This is the peice that actually mounts to the block... Is it held on with 2 14mm bolts under the timing belt cover... The down side is in order to reach them you either have to brake the lower timing cover, or take off the crank pulley bolt which is a pain! I just used some large pliers and pulled the lower timing cover down enough to reach the bolts... Before you put the bracket on the new engine, you may want to have a machine shop trim 1/8" off the front side as some people have had issues with the timing belt rubbing... I had mine trimmed...

Now that your flywheel and bracket are in the shop, its a good time to clean the engine bay... But first, remove the old MAP sensor/Purge control solenoid assembly, with the whole bracket... Its held on with 1 or 2 10mm bolts... Take note where the hose comes from the charcoal canister to the purge control solenoid, and cap that hose off with a screw or something…

Now for the cleaning... I took some degreaser and squirted the hell out of the bay, let it sit for a few min... And then took a towel with some soap and water and scrubbed the bay... Alternatively you can use some simple green, I would have, but I forgot to buy some! You can also scrub off the new engine itself and clean it up real nice... I used a wire wheel on a drill to polish it up some...

Its also a good time to run the wires for VTEC, and the 4 wire O2 sensor... I used the rywire harness, which had a black connector on the end... I simply cut a slit big enough for the 2 inch or so connector to slide thru in the rubber boot in the engine bay engine harness that leads into the cabin... And then I got inside the car, pulled up the carpet, took out the stock ECU, and pulled the harness thru to the ECU location... Plugged in the preOBD to OBD1 harness and the new ECU and I was done there! Quick and easy! The ECU doesn’t fit exactly like the old one did... I just kinda set it in there best I could, and put 1 of the 10 mm bolts back on to hold the cover and ECU in place... Back inside the engine bay, just place the rywire harness with the VTEC and 4 wire O2 connectors out of the way...

Now you can begin switching over wire harnesses... Take the harness off the old engine, but first label the connectors... And familiarize yourself with where they go... Most of them will be pretty much in the same place on the new engine, with a few exceptions... Once you have the old harness off, start putting it back on the new engine... Now you will notice a few connectors don’t quite match up perfectly... The intake air temp sensor (IAT) is now on the rear of the intake manifold as opposed to the side, so you will have to extend those wires... The thermo switch (controls the radiator fans, turns them on at a certain temperature) is now on the thermostat housing, as opposed to the rear of the block by the oil pressure sensor, that wire will have to extended to the thermostat... But also take note that this is the only connector that will not fit exactly on its sensor... You can get a connector from a 92-95 Civic (any model should work) and splice it on... My thermo switch was broken, so I didn’t bother wiring it up... So far (cross my fingers) my engine hasn’t over heated (since time of writing it HAS OVERHEATED! So I just wired up the fans to a switch for the time being, so I highly recommend that you so this!)... One more wire will need to be extended, but its the MAP sensor wire... Its easier to do this when the engine is in the car (simply because u wont know without the engine in the car, the exact location of the MAP sensor), so worry about it then... The new MAP is now on the top of the throttle body...

Now u can also take off anything from the old engine that you’ll need on the new one... On mine the new engine didn’t come with an alternator, so I had to take that off and place it on the new engine... So anything like that, go ahead and do anything like that while you wait on the flywheel...

The fuel line is a bit tricky, I had to use the large dampener pulsating nut and line from my old engine and it worked fine… So you may have to swap that over onto your new engine…

Now if you have an automatic flex plate still on your engine, you can easily (hopefully it will be easy for you as it was for me and my brother) take off the crank pulley/harmonic dampener to get at the timing belt for a change... What we did was stuck a hefty pipe in one of the holes on the drive plate and set it up against the block, and I held it while he used a breaker bar and cheater pipe combo with a 17mm bolt on the pulley bolt... Didn’t take us long at all... Alternatively, u can try an impact wrench if you have one... If you don’t have a drive plate, obviously you’ll have to wait until you get the flywheel back from the shop or something... And even then I’m not sure what you could do... I heard of people sticking a large screw driver in the flywheel but not sure if Id try that... Your just gonna have to figure something out... If you have problems with it, it may be best to just swap in the engine, and take it to a shop to pull that bolt off and have them retighten it a bit... Drive it home and then change the timing belt and water pump... (Your gonna have to look that one up, I highly reccomend u download/buy a Helms manual and follow that, but its fairly easy once u get that bolt off) You can leave the covers off for now if u don’t have the engine bracket back from the shop yet... When u get it in, put it on the block, and put the lower cover back on...

Now the top cover is a little bit trickier... You will have to modify it to fit around the new engine bracket... What I did was, I removed the rubber, and then took a pocket knife with a saw (the kind with the sharp teeth) and cut a chunk out of it, tested the fitment, and then cut some more... You dont want to take too much off so keep test fitting it... When your done take a fine file and file it down so its not jagged, if its jagged it can tear up your timing belt, which is very very bad! Once it fits exact, bolt that baby back on... Miraculously mine looks stock and u cant even tell it was modded!



Now that you have the flywheel back from the shop, time to put it on and make sure to tighten the flywheel bolts to spec, there’s a certain order and u have to do it in stages...

Its in a crisscross pattern and use these specs:
Step1 30 ft lbs
Step2 60 ft lbs
Step3 87 ft lbs

Now install the clutch with the clutch alignment tool, slip the pressure plate on and tighten the pressure plate...

Specs on the pressure plate (also in crisscross pattern):
Step1 10 ft lbs
Step2 19 ft lbs

DOUBLE CHECK YOUR MANUAL FOR PROPER SPECS! These are the specs I used, but double check them!

Now install the transmission back onto the block... I had to slant the block up and rest it on the engine hoist I used and then slid the transmission on... The bolted that baby back in...

Now you should be just about ready to drop the new engine and tranny back into the car... But double check everything!

[Exempt]

IV: Dropping in the new engine

Now that the engine is all ready, hook up the hoist chains and jack the engine up high enough to clear the front of the car... And guide it back down into the engine bay... Careful not to hit the master cylinder, the A/C lines, or anything else... It can be a pain to get it just right... But basically it goes in much like the old one came out... Same angle and what not, the tranny must be pretty low and the engine up high in the air... Its probably best to have 2 or 3 ppl helping out with this, one on each side to make sure nothing is getting smashed in... Also be very careful not to damage the distributor on the new engine... I stuck a large towel between my distributor and the hoist chain and it came out fine... So be careful there as well...

Once the engine is into position start hooking up the engine mounts... It can be a pain at first to get them all lined up... Remember not to tighten them all down just yet because they need to be done to spec and in a certain order... So just for now get the bolts started... I had a bit of a problem with the front transmission mount... Again had issues with the radiator fans... But I eventually got them in...

Once that’s done you can basically just follow the steps for removal backwards... A few things to note though, don’t forget to fill the transmission and engine with fluids they need before you start it up... What I did was I put the axles back on so I could fill the tranny... I filled the transmission thru the reverse switch on the top of the tranny... Its kinda hard to fill the transmission with all those hoses and wires in the way, so I did this first...

Once you’ve got the engine in and in place, there’s a few other things you have to do to finish up the install... The main thing, is relocating the MAP sensor from the firewall to the MAP on the throttle body... Splice the wire, solder in an extension... Solder back on the connector and plug it in... Plug in the rywire VTEC and o2 sensor harness (if applicable)… I also found that the fuel pressure regulator on the new engine, wasn’t the right size for my return fuel line… So I had to swap that from my old engine… Pretty simple task… See if your line fits, if it seems loose as was mine, then swap those over… You don’t want that bad boy leaking gas down into your alternator! You will also have to modify your upper radiator hose a bit… Just fit it on there, and then cut off about 2 inches or so until it fits without a kink in it… Some write ups for the Z6/Y8 say the old lower radiator hose won’t fit, on this engine, it fits fine!

Also on the exhaust manifold, you can use the old stock one, but its more restrictive… If you have the complete header and down pipe from the new engine (doubtful) then you can reuse that… Or buy one from a 92-95 Civic Si/EX… I opted for a decent priced, and great quality Megan header (can be purchased here), the reason is I didn’t want to have to modify anything else, and I definitely didn’t want to run the stock header… If you use the 92-95 Civic Si/EX, or the manifold from the D15B you will have to modify the A/C condenser fan to clear the O2 sensor location… I didn’t have to do this, so I don’t have any idea what all is needed… But I assume with the engine in place you will be able to see it…



And one last thing before you start it up: turn on key in the run position (DO NOT CRANK THE ENGINE) and check for fuel leaks BEFORE YOU START THE CAR! My car was in fact leaking from the fuel line on the fuel filter, I had to tighten it up before I could start the car!

[SiRMarlon]

Nice wirte up TY!! Good Job!

[JDMef90]

Great write up! Helped me alot when I did my swap!