Hello, I’m new here. I recently (foolishly) purchased a 1999 Honda Civic EX coupe with a backyard engine swap. The car started out its life with a D16Y8 VTEC mated to an automatic transmission, but the guy I got it from was a gear head and upon the motor blowing up, he decided to save it rather than scrap it. Currently, it has an imported JDM D15B dual stage VTEC mounted to a 5 speed manual transmission. The car started up and ran great, I drove it an hour and a half home. However, that night I drove it to work and noticed the headlights and interior lights were pulsing brighter and darker. I went into work and came out the next morning about 15 mins before leaving to start it and warm it up. When I came back out after my shift was over, the car was off. The battery had died. I had a buddy give me a jump and went to the nearest autozone to see what I could do. Upon trying to diagnose it, I tried to pop the hood (the pull lever had broken, and the cable was cut and hanging out of the front bumper) and broke the cable off in my hand. So then I had to pull the front bumper, then unbolt the hood latch to get the hood open. The latch is currently mangled and will need replaced. I bought a new battery, since the one in it was 3 years old. I installed it and had the very helpful store team member test the alternator, which he determined that it was completely shot, and not charging the battery at all. I shut the car off, reassembled it(mind you, it’s 8 in the morning and freezing cold out), and drove it straight home. I immediately listed it back on Facebook marketplace to wash my hands of it, but I don’t know… something tells me to just try to straighten it out and keep it. There’s no rust underneath for being a West Virginia car, which is where I got it, and I’m in the Pittsburgh area and am hard pressed to find one with a body in as good of condition due to all the salt they lay down every year during winter. Anyway, here are some things I’ve determined:

-It for sure needs an alternator. The question is, what can be swapped between USDM and JDM? I’m guessing I could get one for a D16Y8 and just make sure it has the same 4 pin connector, but want to be sure before I buy anything. Also, I’m leaving that to the mechanic I trust (I have the Midas touch of breaking things when I try to fix them)

-It for sure needs a distributor seal gasket. It is leaking oil from the distributor onto the top of the transmission. Should I put a new distributor in it, or just change the seal? Again, can I put one on that’s for a D16Y8 on my D15B?

-I am very certain that they didn’t change the wiring harness to a manual one when they swapped the transmission, because I can start the car without pushing the clutch in. I have an electrical gremlin in the form of a non functioning speedometer (tachometer works) so I’m guessing it’s either the speed sensor or something isn’t registering due to the car thinking it still has an auto transmission in it.

-After all the chaos that transpired in the Autozone parking lot, I placed an angry call to the seller who came clean and told me that the ECU is the one that was originally in the car, so a USDM automatic one, and it doesn’t have the dual stage VTEC hooked up, and being that it isn’t for this motor, it won’t work with it.

-performance wise, the car runs and drives fine, but it does seem to miss a little when not accelerating (at red lights or very slow speed) but I suspect that it’s due to the distributor or alternator.

-One of the many perks(sarcasm) of living in Pennsylvania is having to deal with emissions inspection. Any check engine light is an automatic failure, and I currently have one of those. I haven’t been able to see what codes are being thrown, as I’m wrestling with selling it or fixing the alternator first and going from there. I’m not ignorant to the fact that the ECU is going to make it a problem until I change it for a JDM one.

I'm trying to determine the best course of action. It’s a really fun car and I love these cars, even if I can’t really work on them myself, and I need a dependable ride to work and I think if these few wrinkles were to be ironed out, it could definitely get me around for a while. The motor runs strong, the transmission is solid and doesn’t grind or pop out, the body is solid, it’s loud as hell and makes me feel like I’m 18 again.

Thank you for taking the time to read all of this and I eagerly await a kindly Honda guru’s input on this mess I’ve found myself in. Pictured is the car.