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24 Posts
Discussion Starter · #1 ·
Hi guys time for a story with questions at the end.
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I've got a 1999 Bathurst edition that I've been swapping an early '09 Aurion engine into in the comfort of my apartment carpark space.
For you yanks in here, that's an NA rev 3 3SGE engine, and the Aurion is basically a Camry with design work by the guy who made Commodores look good.

So I got everything mechanically done, having followed the videos Gouky made religiously. I downloaded them off Youtube since in 2 stories underground in the carpark ( no reception). I did the same for the wiring, and was a little concerned since hit guide is for a USDM 1993 Turbo, while mine is obviously a bit newer and a non-turbo.

There were some concerns, for example E6 connector had some different wiring configurations, but I probed out the wires that I needed and re-pinned the connector to match the guide.

Same with EA1, though the only difference there was the starter relay ground was in a different pin, and was the Green-red colour indicating factory anti-theft system.
I am 99% confident on this, and am going to test soon with a genuine ground in place of the anti-theft ECU.
The reason I'm reassuring you of this should become obvious in a moment.

I was really struggling with my starter. the solenoid would clack the gear over, but there was no evidence the starter tried to crank at all. I pulled it out, it bench tested fine (popped out and span freely), gave it a few whacks to show it who's boss, then bolted it back in. I checked the alignment of the S54 against the 2GR, everything seemed fine.
Now Gouki's videos are fantastic, easy to follow and obviously the presenter is a well put together young chap :)
But at no point in Video #3 (Wiring) or Video #4 (final engine bay steps) does he mention grounding the engine out.

I figured this out eventually and installed the original small wires and one big chungus:
1 wire from near crank side of block to rear firewall
1 wire from bell housing to firewall
Fat cable from bell housing to left hand engine mount. (I didn't realise this, but the engine mount side was only finger tight from when I dropped the 3S-GE)

I still couldn't crank, possibly because of the big cable's hidden flaw, so I pulled out the jumper cables and proceeded to beat the everliving connect the battery to the positive terminal of the starter and the negative straight onto the starter casing. This produced some desultory cranking, which was a GREAT SUCCESS!! Finally I knew the problem wasn't mechanical and I wouldn't have to tear down my build.
Little did I know, I was about to almost burn it down instead.

I had previously checked the resistance from battery terminal to starter positive, and it was 0.2 ohms or so, and similar from the casing to the chassis. I suspect that a $20 multi-meter isn't capable of testing resistance at hundreds of amps, however, as I believe the resistance would change at higher current (?). I'm not an electrical engineer.

Anyway, since those wires were nominally good, I decided to pop the battery back into the car and try cranking it with a key instead of shorting the starter relay, as I thought maybe my previous success might have loosened the problem up.

I tightened the terminals down nice and tight. Don't want to get any extra resistance!
I turn off the anti-theft by unlocking the car.
I push on the clutch (I don't thin this car has a clutch switch, but still)
I turn the key: CLACK. Nothing.

So I pulled the keys out, wandered around the back and stood there, staring, thinking...
I decided to see if it was the wiring form ignition switch to starter relay, or something else. So I powered the starter relay with a spare external 12V battery.
The car verrrryyy slowwwly cranked. just eking past the compression point.
I was nonplussed, and pulled my probes from the starter relay.

and..... the car kept cranking.

Suddenly I realised I had no way to turn it off. the keys weren't even in the IG switch!
I RAN to the battery. Realised I had bolted it in securely.
RAN to get my ratchet.
RAN back and unbolted the damn thing with shaking fingers in record time.


I went back to the engine bay, and there was a little smoke hovering around the fuse box. Concerned, I pulled up the cover.
it was FILLED with solid grey smoke, more magic smoke than I'd ever seen before!

by now the battery was unplugged, so things were safe. I pulled EA3 and EB1, unbolted the power cables, pulled the fusebox apart, flipped it over...

There was one wire that had lost all its insulation. completely bare. There were goops of insulation on things, so I knew it WAS a white-black wire. This was the cause of the smoke, and possibly (?) the cause of the auto-crank event as well.
This wire terminates at IGN Relay pin 2. that will be a hint to anyone who can read the wiring diagram, as that is normally closed against EB1-1, EB1-4, EB1-5 and the positive sides of VENT and ECU-IG fuses, as in it provides the power to these systems. IIRC these are also continuous with EB1-6, 7 and 8, which power the fuel pump, reverse lights, alt-L and I'm not sure what EB1-6 does. all of this according to the 1993 Turbo wiring diagram linked.

This wire also grounds EFI relay (terminal 4), and the circuit opening relay (terminal 5). I don't know if the C-OPN could have possibly been the cause of the auto-cranking power, as it has a capacitor which might help make it a latching relay? I don't know its exact function.

The wire then proceeds to dive, completely naked, into the wiring loom under the fuse box at this point, so I'm going to have to strip the bugger back to assess/repair damage. The two nearest grounds appear undamaged, so hopefully it doesn't go in too far.

So that's where I'm at.
On the one hand, I'm happy to know the mechanicals is all fine, and I just have wiring work to do.
On the other hand, I burned the F out of a very inconvenient wire, and I'm not 100% sure what caused it. maybe it's just from shorting the starter relay without teh ignition being at least ON.
Formal questions for the crowd to follow.

Here is what it sounds like with pure battery to starter via jumper cables, and independent activation of the starter relay. Not very inspiring, but hopefully it's just the connections. The battery is very solidly above 12V at rest, it went from 12.19 to 12.15 after a bit of this cranking.

24 Posts
Discussion Starter · #3 ·
So. My questions.

What the heck happened? Is there some way the positive power could have flowed backwards up the EB1 connector from some downstream system? injectors,coils, etc?

As I copied Gouky's wiring instructions to the tee, and it is based off the 1993 turbo wiring diagram, I assume it must have been a difference in the wiring of EB1 and/or EA3 on the chassis side. Does anyone have any knowledge of the differences between a late model 3SGE powered chassis and this diagram?
The 5S-FE diagram doesn't have the fuel pump speed relay,which is the same as mine, but are there any other differences I'm not seeing?

How exactly was EA3:8 kept powered to keep things cranking? surely there is no other way this could have auto-cranked.

I failed to mention, but I did find the loose chassis-side connection of the main ground strap after this incident. Are there any other grounds I should add before trying again?
I can't get the throttle body to move with the pedal, are there other grounds I should make for the ECU to help it power up? I don't have OBDII set up yet, so I can only use the throttle activity to indicate ECU power.

Any suggestions of safety checks I should do before I repair the damage and try cranking again (with IG:ON this time).

24 Posts
Discussion Starter · #4 ·
Theres a ground somewhere on the back of the block that if its not connected, it'll cause the car to crank constantly (happened to me and killed a starter)
AHA! so it DOES happen from bad grounding.
I was worried that my wiring was completely alien to the guide's and I'd need to probe out every single wire, decipher ever single relay in the car.
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