iamshane123

As a disclaimer, I am not well versed in Nissans. At heart, I am a Honda guy (let the flaming begin haha) and I have been working on cars for 10+ years. In addition, I do automotive wiring for a living at the local Sheriff's Department, and though I would not consider myself a wiring guru, I am pretty proficient at it.

With that said, I am at a loss right now. This issue of no spark is throwing me through a loop. Hopefully somebody can point out something that I may have just overlooked. Below, I will outline the steps that I have taken to troubleshoot this issue.

My buddy is doing his sr20 swap into his 91 hatch. After setting the new motor in and modifying the harness according to the frsport write up (extending the leads for the MAF and o2 sensor, as well as swapping the KA harness dash connector and the 2 KA chassis harness connectors behind the passenger headlight onto the sr harness), we attempted to start up the vehicle and no luck.

We came to the conclusion that there was either no fuel or no spark. We eliminated the possibility of no fuel but did find out that we were only getting spark on 2 cylinders (1 & 3) and it was very weak on cylinder 3. After using a meter and testing the wires at each coil and comparing the readouts to a running sr swapped I noticed they were the same as the running 240. Tracing the wires back even further, I found that the 5 pin side of the igniter chip was not reading out like the running one. So just to verify, we swapped the igniter from the non-running to the running and the running one started up just fine eliminating the igniter chip as the culprit. We then swapped the coils from the non-running to the running and it started up fine, eliminating the coils themselves. Then, just to be sure, swapped the ecu (E5) from the non-running to the running and still it cranked up and ran just fine.

After these tests, it lead me to believe that the only thing that could still be an issue is the wiring. I pulled the wiring back from the ecu back through the firewall and began to check the pins against a pinout diagram. Sure enough, I found that 3 of the 4 ignition coil signal wires were not in the right pins; and I didn't just trust the colors of the wires, I actually ohmed out the wire from the ignitor connector to where it pins into the ecu. I should also mention here that it is evident that somebody has done some altering to this harness previously as there are some less than quality splices and connections throughout the harness so the fact of some wires being in the wrong pins was not too surprising. After swapping the ignition coil signal wires to the correct pins (1,2,8,9) I thought for sure this would solve the problem. Only ignition signal 1 was in the right pin while ignition signal 3 was in pin 3 (tachometer signal) and signal 4 was in pin 5 (unused) and I don't recall where signal 2 was.

Plugged the ecu back in and checked the 5 pin side connector of the ingnitor chip and everything seemed correct. Tried to crank...and nothing. In fact, now I'm not even getting spark on any coil.

Unplugged the ecu again and decided to go through every single pin to check for accuracy and ohmed out everything that I could to ensure it was the right wire. Ended up finding 4 or 5 more wires in incorrect pins so I went ahead a swapped those around too, though nothing that I can really see causing an issue with spark.

The only issue that I found on the ecu pinout that could maybe be causing any problems is with the CAS 1 degree signal.

CAS 180 degree signal has 2 pins on the ecu (22 and 30) which tie together to one wire about a foot up the leads. I see from the pinout diagram that there is also 2 pins on the ecu (31 and 40) for the 1 degree signals. However, I only have a lead coming from pin 31. Nothing is in pin 40. Now I assume that just like the 180 degree signals, the 1 degree signals would normally tie together to one wire too.

Could this be a root of any of the problems of no spark? Does the ecu perhaps need 1 degree signal coming to both pins to let the ecu know which cylinders to be firing? Or could at least not having that signal put the ecu into a limp mode or something? I'm stumped for now.

So as a quick recap:

Coils are good
Plugs are good
Igniter Chip is good
ECU is good
Re-Pinned Ignition Coil Signal leads to correct pins

*Missing CAS 1 degree signal at pin 40

Here is the diagram I was using...

iRONDONkey

so it turns over?

fuel might be dumped into the combustion chamber.

iamshane123

It does turn over just fine. And I tested spark by pulling a coil, putting a brand new spark plug in, grounding it to the chassis and watching it as somebody else cranks it. No spark at all.

iamshane123

$10 bucks through pay pal for whoever can troubleshoot this!

Dboyizmlg

Is this an OEM wiring harness? Or a pre-made harness ?

s13 harness going in an S13 chassis?

Sorry I didn't read your entire post as it was a bit long and I'm impatient. Lol

iamshane123

OEM blacktop sr20 harness with E5 ecu being swapped into an S13.

Harness has been modified by me per the frsport write up for compatibility with the chassis.

Dboyizmlg

Check out JWT ecu pin out and cross reference with that one.

I think it's going to be the wiring, or chances are might be the ECU.

Did you cut and extend the wires for the ignitor chip?

Double check your wiring!

iamshane123

Well I know the ecu is good because I swapped it into a running s13 with an Sr swap and it did just fine. I didn't have to extend the ignitor chip wiring at all. It's all still intact and like I said I ohmed out betweek the ecu side of the ignitor harness and the ends that plug into the ecu and there was continuity all the way on all 4.
I'll check into the JWT ecu pinout when I get home.

iamshane123

Nobody thinks it might have anything to do with missing one of the CAS 1 degree signal wires?

Kingtal0n

I Wouldnt mess with any of this, seeing how easy the wiring is to do (redtop -> S13 is the simplest there is, 1 hour tops, for you) Just get a brand new oem redtop harness and wire it one time, done. If you think the wiring is culprit. Somebody would have had to mess it up on purpose, however, so it is very unlikely. In other words, you do not touch the cas or coilpack wiring when you wire the sr harness for the lhd chassis, so there is no reason for it to be wrong (unless somebody did it on purpose)

to check for spark pull the plugs, set on a ground like the intake and turn the cas (crank or plug in a spare and spin it)

do a compression test to eliminate air

and all thats left is fuel (if you eliminate spark and air ...)

furthermore, If you have a car with a good harness just swap it over to eliminate it. It only takes a few minutes to pull a harness.

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iamshane123

Like I said in the OP, this wiring harness has definitely been hacked up and messed with. I know for sure there were wire leads in the wrong pins. I've already eliminated air and fuel. I wouldn't be posting unless I had tried everything I could think of and like I said I do automotive wiring for a living.

And yes it would be so much easier to swap the good harness in to check, but the owner of the running car is not a big fan of the idea.

Dboyizmlg

It's always much easier to swap with a working part to confirm if part is operating correctly.

Double check wiring again.

Def

You've obviously identified that hacked up harness is the problem. So replace the damn thing.

As for the root cause of your problem, the owner is obviously a cheap ass, and won't replace messed up parts. That's why the car won't crank.

PM me for my paypal address for the troubleshooting payment.

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iamshane123

Owner isn't a cheap ass...some of us work 50-60 hours a week to make ends meet so continuously forking out money for parts isn't for everyone especially when it may or may not fix the problem. There is seriously no reason to be rude like that but thanks anyway.

With that said, we finally swapped the brand new wiring specialties harness in and it started and ran for a few seconds, and now back to no spark.

Any other ideas?

91ka24

maybe the ground for the coilpacks is loose? it is on the back of the head

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mogli9000

1) Check timing.

2) Check coilpack wiring

3) Check grounds and add more grounds

4) Check CAS

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