*HELP* 2000 Honda Civic dx hatchback engine swap
 

I've recently acquired myself a 2000 Honda Civic dx hatchback and it runs but the engine needs massive work. It's currently got a d15b engine in it which I'm not sure is the stock engine.
I've found a nice d16y7 engine and I'm wondering if I can swap that in.
Basic questions:
1) is it compatible?
2) what parts would I need to compete the swap and is there any excess wiring or electrical changes needed

The d16y7 is what would have been stock in any 96-00 hatch in canada, so yeah it should work. The main questions I have for you to answer your questions tho are what has been changed on the car for the D15b? Is it VTEC, is the manifold from the original y7 motor still there or is the one for the D15 there? What ECU is in the car? and how complete is the y7? manifolds, both in and ex, distributor, sensors, throttle etc?

If it's a VTEC motor, then it may or may not have been wired for VTEC, and as such may or may not be running the original ECU. If the car was wired and the ECU swapped, the new y7 will throw codes for the VTEC components it of course doesn't have. Chances are tho if it has been wired, that a couple wires were added, they won't hurt anything converting back, and the car may or may not have been converted to OBD1. I'm not familiar with how smog testing is in Alberta entirely, I know some parts have none, but out here, a lot of 98-00 Civics went up for sale because they were swapped and converted back to OBD1 and not worth the hassle of getting there swap running OBD2 a/b considering the cost of doing so vs your typical broke ass Honda kid in TO. Either way tho since your car is still a D series and you're going back to the stock motor, this shouldn't be a problem for you. If it's converted most people just add a conversion harness from the car harness to the ECU, simply remove that and put a stock 00 Dx ECU in, auto or manual ECU according to what trans you have.

If the car is still running OBD2 then the alternator and most sensors should be the same, if the stock exhaust manifold is there (has a cat as part of the manifold with and O2 sensor before and after the cat) then everything should all work, the distributor may be different for a VTEC head, not 100% on that tho, I know the physical dimensions for a V/non V dizzy are different on B series, but internally is what I'm not entirely sure with the D series, I don't remember there being a difference in components but something about the spark advance.... basically if the new motor doesn't have a distributor, try it with the old motors, if you get codes for CKP, CYP or miss fire codes, chances are it's the dizzy provided the motor didn't have this problem before.

Most importers sell D series motors for around $400 here and in BC, again not super familiar with Edmonton, never lived there, just stayed a few days once or twice

Trans and mounts will all bolt up, and if the VTEC isn't wired/connected etc (if it is a VTEC some d15b's were, some wern't) then you can simply drop the entire swap, motor trans axles, steering rack, sub fram, knuckles suspension etc (PM me if needed and I can give you a list of how I drop D series Civic motors in under an hour) Then just swap everything over from the B to the y7, and then install it all back in. Done properly and with a hoist I can have these swaps done before lunch. In a driveway, that's kinda a different story, sorta depends on what tools you have and how you can lift the car and or the swap. Driveway style I'd still drop the trans if it's manual cause it's way easier to put the motor in then add the trans then do it the other way around. Auto trans you don't have an input shaft and clutch to line up and can slide the motor down past it easier.

Good luck with the swap and any questions I didn't cover please ask.

Thanks very much for the write up, that was very thorough.
As far as the intake, exhaust and distributor set up they all look like they belong to the d15b engine
However the d16y7 that I can get comes with the engine fully equipped (may not get the exhaust manifold/intake with it) harness, transmission, axles and ecu. the car has an after market basic cold air intake on it, and a magnaflow exhaust as well.
Im going to be doing the swap in the shop with a hoist and I have all the tools necessary to get the job done.
the d15b that has been dropped in there is not currently throwing any codes and is a vtec model so I'm positive wiring has been done to run the ecu
If I swap the engine, put in the harness with it and run the ecu that comes with it then it would put it back to stock yes? Will any of the additional wiring interfere with installing the old stock engine back in?

Yeah I just confirmed with the engine I get:
Fully equipped with distributor/ignition set up
Engine harness
Ecu
Manual transmission assembly
Axles
Intake and exhaust manifolds
With all this I should be able to revert it back to stock without too much difficulty I'm hoping. The only thing I'm still unsure of is the wiring conversions they would have made to convert it to the d15b.

ok well then there are 2 things to consider, one is what trans is in there and which gears would you prefer shorter or longer assuming that the trans is from a VTEC motor as well it'll have shorter gears that are a little nicer then the tall non V gears.

as far as wiring goes depends on how the swap was done. If they used a conversion harness and OBD conversion on the car, then you should have a jumper harness plugged into the ECU that likely is where VTEC is tapped into. Unplug that harness and plug the new ECU into the stock harness, and use the new motor with its harness and it should be all you need. I guess you're first step is to follow the 2-3 wires on the VTEC solenoid and see how they get from there to the ECU

It looks like when they swapped the engine to the d15b that they also swapped in a different ecu. The wiring to it is a bit of a mess but it's definitely not the original ecu and not the original engine.
I traced all the wiring and found that it looks like they haven't messed with anything else but there is a rats nest next to the ecu. I'm going to check in and around that to see if anything else has been wired in but it looks like they just did a direct swap and found the appropriate ECM for it and did some minor wiring.
So if I just ripped that engine out and the harness and ECM I'm pretty sure I wouldn't have any issues. I just think they may also have converted it to obd2 off the ECM. How would I go about correcting that?

the car would have been obd2 originally, basically if they put in the matching ecu for the motor and it was an obd2 engine, they likely only added in wires for VTEC, one for the solenoid power and one for the pressure switch. As long as there's no butchered wires under the dash I'd swap in your entire new setup, and plug in the ECu then see what happens. The VTEC wires not going to anything wince there of course no where to go, won't do anything to the ECU. The wires for VTEC if the current engine has a proper VTEC harness, would then be tapped into in or around the pass side strut tower connector where the engine harness connects to the car harness, from there to the ECU, if They did a proper job and added the VTEC wires to the harness at those connectors, then the new harness connector just won't have anything on the other side and bonus will protect that connection should you later swap back to a VTEC motor