S14 Kouki SR20det Wiring Harness Help

[Mr. white]

So, My wiring harness was pretty haggard. I took it upon myself to try and fix it up. I did pretty well. lots of patch work and sleeving. I wired everything up to the pin out sheet I found for the harness online. I throw it in the car and get power to everything as is. Fuel pump primes, 12V to circuits. But, it won't start anymore. I know there are issues with it, obviously, since it started prior to my tinkering but just looked bad. over the past two weeks I have done lots of researching on things it could be and cannot find a solution. So, I will give a rundown of everything I'm experiencing and hope for the best.

I went through the circuits using a Zenki diagram because I cannot find a Kouki one anywhere. As of now, this is what I have experienced.

Initially
- Signal and power to CAS (Unplugged)
- Power to Coil packs and injector harness
- Power to coilpack side of igniter
- Power to ECCS relay (one side sees 12V other doesn't, thought this was normal but could be wrong?)

^This lead me to believe that is was an issue that there was no signal being sent to tell the car to start (no voltage from ecu side of ignitor or signal from coilpacks)

Now, here is where shit gets weird:

- When the CAS is plugged in, I get 12V but I get no signal voltage to those wires
- ECU side of igniter has no voltage going through in either ON or Start position
- Orange start signal wire on dash plug get 9 volts
- With injector ground connected, fuel pressure drops as soon as car stops being cranked

I started fucking with the grounds, only to find that:
- Igniter ground disconnected yields voltage to all ECU pins AND voltage to coilpacks
- Injector ground disconnected yields same results to injector connectors, Fuel pressure remains steady after cranking stops
-Disconnected CAS ground. Voltage with CAS connected at 5 volts.

Car still won't start.

Looking for some help on what to fix. Any ideas??

Thanks,

Lawz

[Kingtal0n]

Hmm. Its been along time since I wired one of these. Good job trying to do it yourself...

I think that part of your issue is simply that you are trying to hard, and going too far. Most of the wiring is done right at the F3 plug, we dont fool with the igniter wires or CAS wires, heck i've never even checked one. The ECU itself is supposed to plug into a harness that directs these wires to where they go: You do not fool with any of them.

YOUR job is just to connect the chassis F3 plug to the engine harness so your car can
A: power the ECU (and in turn the ECU triggers back into the F3 plug for the fuel pump)
B: ground the ECU
C: communicate (gauges) with the ECU
And there are a few other misc. wires involved with
D: A/C
E: Wipers (which are in essence, their own separate harness, they just happen to get packaged in with the engine harness at some length)

You have lots of options, fear not. If you think your engine harnes is f'd you could always source a next one (they should be $50-$100 since nobody ever uses them anymore. I know somewhere theres a whole warehouse full of em) and you could even grab a zenki harness and use the WC ecu instead of the NA ecu that is used for the kouki harness.

[Mr. white]

Appreciate the response. I wasn't very clear in mentioning that this is in an S13. The harness was working. but, I wanted to attempt a wire tuck. I cut the harness to length and wired everything up using a zenki pinout.

[Kingtal0n]

Well then. I am not sure how anybody could help you, since whatever changes you made to the harness only you would be aware of. If there are continuity issues you may as well open it back up, and trace your wires. You could always de-pin the harness at the ECU, and use a completely new wire, re-pinned, the right shape and length for your purposes.

[Mr. white]

I understand where your coming from, but I'm only looking for one of two things:

1. Someone who has done the conversion to chime in
2. confirmation of what pins to look at and how the wiring should be that could help isolate my issue (no spark).


Why would disconnecting a ground result in me getting signal and power to the coilpacks, but it not starting?

[Mr. white]

Update:


Fixed some things, the fuel pressure holds steady now. But, still not getting spark and injectors are not firing.



After some tests and fixing the wiring some:
- I get 12vs coming from the Coilpacks wires down to the igniter.
- I get 12vs to Injector power wires.
- Cas gets signal and and 12v
- Ignition wires 1,3,5,25(Kouki Harness) do not have any voltage with key in ON or START position. I believe this is why I have no signal with the connector unplugged.
- With injector wires unplugged, If I test for voltage, it begins to read and drops down to 0 , eventually.
- Orange Start signal wire not getting 12vs

I just want to confirm that the orange wire from the dash is suppose to get 12v and sends signal to both injectors and ignition wires? Should it read voltage with key in ON position or only START? I have read mixed answers to this question when I searched.

[Mr. white]

Can anyone atleast tell me if I'm in the right direction?