tailoredtune

i am replacing the entire wiring harness on my 88 civic ef, it has a DOHC ZC in it and the previous owner spliced the hell out of the connectors going to the ecu. this is why i am redoing the entire wiring harness. but i am finding out that the wiring harness does not come with the fuel injector harness. does anyone know where i can get one?

crx_si-r

The fuel injector harness is built into the ecu (main) harness and in the engine harness.

tailoredtune

thats what i thought as well but there isnt any conectors for the fuel injerctiors. i will post pictures tonight to help you understand because i know my lack of knowledge in this department and terminology might be confusing haha

BigD4207

there's not going to be either, factory motor came with a dual point (throttle body) injection with only 2 fuel injectors. when swapping a dohc zc or any mpfi motor, new wires have to be ran to the ecu for the other 2 injectors and other 2 spliced in from other locations. if its the connectors that the actual injectors plug into you're missing, then you will have to go to a salvage yard and grab some from a mpfi motor, hope this helps

oh and btw....i got a trailer connector (6 pin i believe) to disconnect the injector wiring if i need to, makes it easier if you ever have to drop the motor or anything, and make sure you wire the injector resistor box back in to the system, do not leave it out, you'll fry the injectors..it's something that should be there from the swap, didn't come with one originally so it may be ghetto wired too, it'll be a silver box, either square with heat sink casing, or a rectangular "twinkie" looking box

tailoredtune

Big that was a alot of help, i dont know where the injector resistor box would be located so idk if i have it. chances are that if i havent seen a silver twinky box i dont haha. here are the pics i promised to help yall see the big picture.

this is what im talking about (fuel injector wires). they are wraped in electrical tape (and that melts in this texas heat).


another view of them


they are then unwraped at this point and continue through the firewall to plug into the ECU....so ghetto


the red box is the old connection that was used to plug into the ECU, some of the splicing that was done is so bad it has bare wire flailing about (it would touch another metal and start to pour fuel into my cylinders).

the blue box is the new connector for my ECU. am i going to have to splice into this new connector like the previous owner did?


i have a ZC DOHC and the wiring harness i got is for a 89 civic si which should be, and has been, plug and play.

tailoredtune

essentially i want to get ride of the spaghetti look and make it a more secure reliable connection. so i do want to replace those fuel injector wires.

BigD4207

def needs a re wrap, not necessarily re wired unless there's breaks/cracks in it, best bet would be to re wrap it all with high heat tape and get some wire looms and zip tie it every 6 inches so the wires don't have room to twist and break, same at the ecu, and all connections need to be soldered: you don't want these losing connection going down the interstate...the resistor box is usually put over on the driverside shocktower or somewhere around there, it might just be a little box but by the looks of your pix it should be somewhere down the line, this is obdo right? if so it must have one, trace the red/black wires (4 of them, one for each injector) and see where they go, they should be at the box. lol....looks a lot like my engine did, i couldn't find high heat paint that turned that red though, mine looks a little more orange-ish, i got all red looms for engine top harness, and black for all grounds/bottom engine/trans wiring, makes it look nice

BigD4207

oh...and btw...si harness is different at the dizzy, it has a single connector if i'm not mistaken and has to be switched to the two connectors for the zc distributor, dx/lx had the dual dizzy wiring but with dpfi, si had the mpfi wiring but single plug dizzy or something along those lines lol

tailoredtune

huge help man, now i can stop looking on c-list for the part and just get my hands dirty! ill look for the resistor box this week and let you know what i find. also, i only got the 89si underdash harness that plugs into all the accessories as well as the headlights and stuff. i didn't get the engine harness so i shouldn't have to worry about dizzy connections haha but that information will serve me well in the future!

BigD4207

glad i could help, just remember to solder all connections and wrap the hell outa everything, like i said i wrapped with tape, then loomed and zip-tied every 6 inches, it'll guarantee nothing inside the looms breaks or twists free, good luck on the project man, the zc is a pretty nice motor, it's what i have and i like it for what it is..oh and since you don't have a connector for the injectors, it'll be a lot easier to place one, either from a junkyard injector connector, or like i did and get 1 or 2 trailor connectors, it'll make it so much easier if you ever have to drop the motor or just get the wiring out of your way.

OneBadTurboCRV

I just peeked in and wanted to say... MY EYES, WHAT HAVE YOU DONE TO MY EYES??? WHY WOULD YOU SHOW THAT TO ME???

Alright, enough fun for one post... Is that speaker wire I see? I am glad you are going to fix that, because if you weren't going to then... well I just won't go there.

BigD4207

Oh....and one other thing tailoredtune...check the wiring from the cps (the sensor on the side of the exhaust cam, in front of the dizzy with a green plug) to the ecu, this is something that had to be wired in as well, especially if it's not wrapped or anything just get some 16 awg and run the 2 wires, that sensor and the mpfi conversion is all it takes to run the zc..along with the ecu of course, and do yourself a favor and check the wiring to the plugs for i believe the air intake temp sensor and throttle position sensor they are the one on the side of the intake manifold and on the back of the throttle body, these needed to be lengthened to fit the zc, just make sure they have good connections and should be good (eacv might have been one, can't remember but just do a runthrough behind the intake manifold plugs)

tailoredtune

N3va i agree with how scary this wiring was done and i can tell you right now i have cleaned it up, organized, and made better connections! big, you brought up my next question with your information about the intake wiring. one connector on the harness doesn't match up to the existing connector on the engine harness. the existing connector has 8 wires leading into it and the new connector only has 5 or 6 (cant remember of the top of my head). either way i dont know how to get this to work. the car wants to crank but it wont catch and i have a strong feeling its because of this intake issue. any suggestions?

this is the existing connector




this is the old connector



new (on the left) vs old connector


new (on the left) vs existing connector



i try to give yall as many pictures as possible to help you see what the heck im trying to fix haha

4drEF

I have no idea what you are doing.
It looks like you picked up an engine harness, but clearly it's not plugging into your shock tower plugs.

You can not just plug in any engine harness into your car.
It won't work.

You should be using the original engine harness that came with your 88 Civic and modifying it to work on the ZC engine.
Way easier.
I know you don't have one as you bought it all cut up from the previous owner, but that's where you should be starting from.

tailoredtune

I agree but I was under the impression (due to research and asking of info elsewhere) that the 89 civic si wiring harness would be plug n play with the 88 ef engine harness that is currently in place. the intake connector is really the only problem when it comes to plugging in. i don't want to go and buy another engine harness if i can fix this with what i have haha thanks for the advice 4dr i might have to look into another engine harness if something doesn't spark in my head soon!

OneBadTurboCRV

They are not "plug and play"... One is MPFI and the other is DPFI. Also, if you look on the passenger side shock tower you will have 3 plugs instead of 2 on the engine harness... and that's just the beginning.

tailoredtune

i did notice that come to think about it, is there a way to fix it without getting a new engine harness cause im a little strapped for cash, or do i need to go ahead and get a new engine harness. if so do i need to get a 89 civic si engine harness and will that plug up to the zc?

4drEF

It will plug in to the ZC motor, but it won't plug into your shock tower plugs.
You will have similar problems to what you have right now.

You should be getting the engine harness that came OEM from factory for your car.
ie: If you have an 88 DX, then get a DX and not the Si.

tailoredtune

sweet, 88 ef engine harness and that will plug into the 89 si engine harness that is under the dash, or do i have to have to get an 88 ef harness for that too?

jlicrx

i don't recall you ever saying what model your car is? - from the chassis harness connectors coming out of the firewall, it appears to be a DX - confusing when you say the chassis harness (from ECU to firewall) is 89 Si, since it doesn't appear to be from an Si

if it were mine, i would get both a chassis harness and an engine harness for the car you have and start from scratch - if it is a DX, get the DX harnesses and then do the DPFI to MPFI wiring changes - follow the attached pdf for making the wiring changes - it appears that you have everything needed to make the changes, like resistor box and injector wiring

tailoredtune

the car is a 88 ef, the chassis wiring harness is a 89 si and the engine harness should be the stock 88 ef (unless the previous owner changed it but i dont think he did). so ill look for a 89 si engine harness and go from there. ill look at ZCspeed for more info on the wiring changes.