S13Morgan

I'm doing a swap for a friend of mine and im swapping a gsr motor into his 99 civic coupe. I know I need a 99-00 si t bracket and i have to run the wires from the vtec solenoid to the ecu, which is a 98 gsr ecu. What other wiring needs to be done to make the motor work with the stock wiring harness from the civic?

Hes using innovative mounts, and I already pulled the timing belt side motor mount bracket off an ls motor i had laying around. I also have a stock wiring harness from a 94 civic laying around that had a plug that was the same as the green plug on the vtec solenoid, is there any other plugs off the 94 harness that i could use to wire the motor?

He got a 98 gsr distributor also, which the plug isn't the same as the one on the harness. What is the easiest way to make it work? do they make a plug n play harness thing or could i get the correct plug from somewhere and splice it onto the distributor?
I also already have the integra axles and hasport shift linkages.
Any and all help will be greatly appreciated.

dohc_sedan

em1 wiring harness

Vindicator9000

I've got an 01 B18C1 in an 00 Civic, which is pretty close to what you're doing, since 99-00 Civics are pretty much identical.

Someone (I forget who) does sell a distributor jumper harness to make it plug and play.

I didn't need it on mine though. I spliced on the dizzy plug from an Integra harness. Honestly though, it's been 2 years, and I can't for the life of me remember how I did it... Actually a friend did most of that part of the swap. I believe that the Civic harness is 8 wires, and the integra is 10, but the extra 2 pins are just for shielding, and only go down into the loom like 8" and stop. Everything else, if I remember correctly, you just match colors. Please do us all a favor and splice it right, using a soldering iron and heatshrink.

As far as the rest of the harness... I KNOW if you have an EX, you don't have to run vtec wires, but not sure about the other models. I think you do have to extend the existing vtec wires though. You'll also have to extend the evap purge if you're running the later USDM GSR intake manifold with the evap on the top.

I believe you'll have to extend the IAT wire. On the Civic, it's on the intake arm, but on the teg it's on the manifold. Or you could leave it on the intake arm, if you can find a way to make a Civic arm work with a GSR. My Civic arm wouldn't fit right on my GSR manifold. I used an LS arm from the junkyard, cut roughly in half to fit, into my stock Civic airbox.

Do yourself a favor and extend the fuel return line while you have the engine out. It's on the driver's side firewall, and the Civic softline will be too short. All you need to do is replace it with a longer one, but it's a MAJOR pain to get your hand back there once the GSR engine is in.

If you're running the GSR intake manifold, you'll need to run a wire for the IAB solenoid, and you'll need a small, round 2-prong female connector to go on the end of the wire. Since you're running a 98 ECU, the wiring will be different from mine, and I can't really tell you more beyond that. There is info out there on that though.

You'll probably need an OBD2b to OBD2a ECU jumper harness. Not entirely sure if the 98 Teg is 2a or not, but I think it is. I know a 99 Civic is 2b. Without that, it will be a major pain to rewire the entire ECU harness.

You will very likely find that the flange on the Civic cat is clocked backwards from the Teg header. I know it is on the 2000 Civic, and assume it is on the 99 as well (unless you have an Si... then it's right). You may also find that the Civic exhaust is slightly too short for comfort. Mine was. The easiest way to fix this problem is to take your cat to an exhaust shop. Have them cut the front flange off and weld in 2-3" of extra pipe. Then weld the flange back on 180 degrees backwards from where it was. When you get the engine in, you'll see exactly what I'm talking about if you have that problem.

You'll need a Teg throttle cable. I couldn't get the Civic one to fit right; it was too short, I think. The Teg cable was too long. I used the Teg cable with a couple of zipties behind the pedal to take up the slack, and it's worked great for over 2 years.

If you're retaining A/C, you'll need the AC mount bracket from a 99-01 CRV. For power steering, I believe I was able to use the Integra pump, but I've heard its a crapshoot as to whether the hoses matchup right, depending on what year Teg your pump is from.


Here's my swapthread that gives a pretty good rundown of what I ran into. The 99-00 Civics ARE a little different to swap than the EGs, and most people don't realize that. https://honda-tech.com/forums/honda-civic-del-sol-1992-2000-1/swapguide-00-01-b18c1-into-99-00-civic-lots-pics-2334716/

HondaPartsHero

Yeah depends really on your model coupe for the wiring portion (this is assuming the B18C1 is OBD2 if its OBD1 then there will be a few more things):

DX/LX (D16Y7)
-wire VTEC solenoid, VTEC pressure switch, knock sensor, IAB's
-extend primary and secondary O2's
-wire IACV from 3 wire to 2 wire
-IAT needs to be placed in the intake arm or use round style plug and swap it over
-CKF sensor needs to be bypassed or swapped for a two wire style plug
-distributor adapter or swap over internals

EX (D16Y8)
-wire up IAB's
-extend primary O2 sensor
-IAT needs to be placed in the intake arm or use round style plug and swap it over
-CKF sensor needs to be bypassed or swapped for a two wire style plug
-distributor adapter or swap over internals

S13Morgan

how do i change IACV from 3 wire to 2 wire??

cb07

Great info in this post

HondaPartsHero

Vindicator9000

^^^Katman's diagrams are great. I wasn't aware of the IACV fix, I guess because I have an EX.

Only big problem is that he's running a 2a ECU in a 2b car, so he'll still need a jumper harness. The alternative is running a 2b P72, and then he'll have to deal with the immobilizer if it's USDM.

HondaPartsHero

Yeah didn't catch that, I believe the iacv fix will still convert over but he'll still need the conversion harness for the ecu as u pointed out