3sgte Custom loom for atom

[Whitey]

Hi guys, I am about to embark on making a loom for a gen 3 3sgte. The reason for not using a pnp was its application. It's for an autograss car which is essentially a tubular frame with an engine. The standard loom was not the right length etc.

I have made a loom from scratch for an escort cosworth which used an omex which I converted to distrubutorless / wasted spark. So I am not completely useless.

I plan on using the distributor for the engine speed references but a wasted spark coil of some type.

Is there anybody that has gone down this route before? Or have a typical wiring diagram so I can confirm what I think is right. I have tried the search function but seem to only find pnp topics.

Also does the ecu utilise the use of the ICV? 

I'm sure I will have more questions along the way.

Many thanks 

[Adamw]

A generic 4 cyl wiring diagram attached below.  The only change would be you will only need to use Ign 1 & 2 for wasted spark and the "cam & crank" sensors would actually both be inside the distributor.  If the wasted spark coil is a dumb one like from a ford or vauxhall then you will also need a two channel ignitor between the ecu and coil.  The VW golf coil is a good wasted spark one that doesnt need a separate ignitor.  

Monsoon-4-Cyl-Generic.pdf

[Whitey]

38 minutes ago, Adamw said:

A generic 4 cyl wiring diagram attached below.  The only change would be you will only need to use Ign 1 & 2 for wasted spark and the "cam & crank" sensors would actually both be inside the distributor.  If the wasted spark coil is a dumb one like from a ford or vauxhall then you will also need a two channel ignitor between the ecu and coil.  The VW golf coil is a good wasted spark one that doesnt need a separate ignitor.  

Monsoon-4-Cyl-Generic.pdf 50.48 kB · 1 download

That's a great diagram thanks. The extra sensors I assume can be map, knock, lambda. I have these fitted so it would be worth using them?

[Adamw]

9 minutes ago, Whitey said:

The extra sensors I assume can be map, knock, lambda. I have these fitted so it would be worth using them?

Yes this diagram was for a Monsoon which has a MAP sensor built in.  In your case you will need to connect the MAP just like one of the "extra sensors".  Lambda would typically be only one or 2 wires, it would not have a 5V supply from the ecu - but yes it will be connected to an AN Volt pin and possibly sensor ground (Gnd out) if your device has a separate analog ground.  

For the Knock sensor, first check your Atom is hardware revision V3.0 or later (check in PC Link >help>ecu information) as knock was only added to the Atom recently.  If your ecu is capable then the knock sensor needs to be connected between the dedicated knock pin and one of the sensor grounds shown below.

[Whitey]

40 minutes ago, Adamw said:

Yes this diagram was for a Monsoon which has a MAP sensor built in.  In your case you will need to connect the MAP just like one of the "extra sensors".  Lambda would typically be only one or 2 wires, it would not have a 5V supply from the ecu - but yes it will be connected to an AN Volt pin and possibly sensor ground (Gnd out) if your device has a separate analog ground.  

For the Knock sensor, first check your Atom is hardware revision V3.0 or later (check in PC Link >help>ecu information) as knock was only added to the Atom recently.  If your ecu is capable then the knock sensor needs to be connected between the dedicated knock pin and one of the sensor grounds shown below.

It is a brand new atom received it this week so it should be.

I was going to use the ford type wasted coil as I have a new one here. It has 3 wire plug. I'd assume it needs an igniter?

When I used the same type coil fitted to a cosworth running an omex I didn't use an igniter, makes me think that I should have? What does it do?

[Adamw]

25 minutes ago, Whitey said:

I was going to use the ford type wasted coil as I have a new one here. It has 3 wire plug. I'd assume it needs an igniter?

Yes you will need an ignitor with that coil.

 

25 minutes ago, Whitey said:

When I used the same type coil fitted to a cosworth running an omex I didn't use an igniter, makes me think that I should have? What does it do?

I dont know the omex well, but it looks very oldschool, 1990's technology, suspect it is based on one of the old GEMS designs.   Back then many ecu's would have ignitors built-in as all coils were dumb coils.  Most modern ecus have moved away from that as dumb coils are rare nowadays and ignitors are easily damaged with something as simple as a wrong dwell setting.  In the old days a damaged ignitor would require shipping the ecu back to the manufacturer for repair.   

[Whitey]

42 minutes ago, Adamw said:

Yes you will need an ignitor with that coil.

 

I dont know the omex well, but it looks very oldschool, 1990's technology, suspect it is based on one of the old GEMS designs.   Back then many ecu's would have ignitors built-in as all coils were dumb coils.  Most modern ecus have moved away from that as dumb coils are rare nowadays and ignitors are easily damaged with something as simple as a wrong dwell setting.  In the old days a damaged ignitor would require shipping the ecu back to the manufacturer for repair.   

Thanks for the info. You've been more than helpful.

I brought a 3 port boost solenoid so that will use another slot I'd assume an aux one? Not sensor

 

[Adamw]

4 hours ago, Whitey said:

I brought a 3 port boost solenoid so that will use another slot I'd assume an aux one? Not sensor

Yes, connect one wire of the boost solenoid to any aux.  connect the other wire to the point in the drawing "+12V other relays, VVT, Idle valve, etc".  I see I missed a question earlier about the idle valve.  Is the idle valve a 3 wire one similar to an ST205?

[Whitey]

6 hours ago, Adamw said:

Yes, connect one wire of the boost solenoid to any aux.  connect the other wire to the point in the drawing "+12V other relays, VVT, Idle valve, etc".  I see I missed a question earlier about the idle valve.  Is the idle valve a 3 wire one similar to an ST205?

Yes I'm sure it's 3 wire

[Adamw]

Generally the older toyota 3 wire idle valves such as the MR2 used need to be connected to aux 1 & 2.  So, the bentre pin goes to +12V, one outside pin goes to aux 1 and the other to aux 2 (doesnt matter which is which). 

[Whitey]

3 hours ago, Adamw said:

Generally the older toyota 3 wire idle valves such as the MR2 used need to be connected to aux 1 & 2.  So, the bentre pin goes to +12V, one outside pin goes to aux 1 and the other to aux 2 (doesnt matter which is which). 

I can see me running out of aux ports. 

So I will need them for fuel pump, rad fan, 2 get used on the idle control, boost control solenoid and I planned on using one to turn on the charge cooler pump once the engine was running.

Did I read somewhere that the unused coil channels can be used in this way?

[Adamw]

Yes, if you use distributor ignition you can use the 3 spare ignition outputs as auxes.  Or you can do COP coils wired in wasted spark which will give 2 spare auxes 

[koracing]

On 12/17/2021 at 12:20 PM, Adamw said:

Generally the older toyota 3 wire idle valves such as the MR2 used need to be connected to aux 1 & 2.  So, the bentre pin goes to +12V, one outside pin goes to aux 1 and the other to aux 2 (doesnt matter which is which). 

Are you saying it doesn't matter which is which because you can switch the direction it works in the ecu (Aux 1 Active state setting perhaps)?  

[Adamw]

Yes, Active state setting changes open/close direction.  Forgot to mention above you can also use Aux 3/4 for 3 wire valves in G4X.

[Whitey]

Ok well into wiring this now. Couple of more questions.

Engine speed from distributor I have-

Ne-yellow 

G1-red

G2-blue

G- -black

I assume there will be a 12v feed to one of these and trig 1 & 2 to others? Do I need to earth the shield anywhere?

 

Ignitor has a 12v feed to b+ and the positive on the coil and I assume I use the igt wire as the ign1 to control it?

 

Thanks 

[Vaughan]

1uz is functionally identical to the 3s from memory.

[Whitey]

Spot on. I take it sync#2 n/c means not connected? And the view is looking at the back of the plug?

Have any info on the tps? Think I have 4 wires going to mine

[Vaughan]

1 hour ago, Whitey said:

Spot on. I take it sync#2 n/c means not connected?

yes nc is no connect.

1 hour ago, Whitey said:

And the view is looking at the back of the plug

diagram looks like it is looking into the distributer plug. I have attached some more pictures and the picture of the plug appears to be looking into it from the distributer side not the loom side. G- (pin 4) is signal ground, NE (Pin 1) is Trig 1, G2 (Pin 3) is Trigger 2.

1 hour ago, Whitey said:

Have any info on the tps? Think I have 4 wires going to mine

I used the attached pdf when making a custom loom for my 3s,  TPS pins are numbered the same as the distributer. Pin 1 is signal ground, pin 2 is unused (idle switch), pin 3 is An Volt signal, pin 4 is 5V. (pdf page 57, 56 printed on page, for the sensor wiring and pdf page 64, 63 printed on page, for the pin numbering on the plug, T2)

http://www.cannell.co.uk/Workshop_Manual_Toyota/MR2_ELECTRICALWIRINGDIAGRAMS.PDF

[koracing]

Interestingly (or possibly not depending on what one finds interesting) about the wiring of the G1 or G2 on the distributor is they are identical reluctor sync signals "180 deg" apart from one another on the cam (360 deg on the crank).  Either one could be used depending on where you set the trigger offset.  If one were to ever fail, it may be possible to switch the trig2 wiring to the other and change your offset angle by 360deg.  Link's base maps for the 3SGTE are set assuming you are using G1 as the Trig2 (pin 2 in the above diagram), but as I said, it shouldn't matter which one you use if you get the trigger offset correct.

[Vaughan]

1 minute ago, koracing said:

Interestingly (or possibly not depending on what one finds interesting) about the wiring of the G1 or G2 on the distributor is they are identical reluctor sync signals "180 deg" apart from one another on the cam (360 deg on the crank)

I was under the impression that G1 was 2 teeth and G2 was a single tooth but I could be wrong

On a 3s that is, well aware 4agze is 1 tooth but 180deg out on the sensor (360 out on the crank)

[koracing]

6 minutes ago, Vaughan said:

I was under the impression that G1 was 2 teeth and G2 was a single tooth but I could be wrong

No, it's the same single tooth with two different magnetic pickups 180 apart in the distributor housing.

The tall magnetic pickup is the crank position, and the lower ones have a single tooth under the 24 tooth wheel that passes by them.

As far as I'm aware, Toyota used this same basic trigger setup for most vehicles with distributors from mid 80s to the late 90s.  Even the non-vvt 2JZ with COP is still a 12 tooth crank (which would be 24 tooth on a cam), with two single sync reluctors 180 deg appart off the intake cam if my memory serves me.

12 minutes ago, Vaughan said:

I was under the impression that G1 was 2 teeth and G2 was a single tooth but I could be wrong

On a 3s that is, well aware 4agze is 1 tooth but 180deg out on the sensor (360 out on the crank)

4AGZE trigger setup is the exact same as distributor 3SGTE -- the same offsets work great also BTW.  

[Whitey]

Thanks guys very helpful.

 

Out of interest do you use a relay to activate the boost solenoid (3 port link one)? I had a chat with the tuner I am going to use and he said not connect direct to the ecu

[Adamw]

The boost solenoid needs Ign switched +12V to one wire and the other connected directly to an ECU aux.

[Whitey]

Thanks

[Whitey]

20 hours ago, Vaughan said:

yes nc is no connect.

diagram looks like it is looking into the distributer plug. I have attached some more pictures and the picture of the plug appears to be looking into it from the distributer side not the loom side. G- (pin 4) is signal ground, NE (Pin 1) is Trig 1, G2 (Pin 3) is Trigger 2.

I used the attached pdf when making a custom loom for my 3s,  TPS pins are numbered the same as the distributer. Pin 1 is signal ground, pin 2 is unused (idle switch), pin 3 is An Volt signal, pin 4 is 5V. (pdf page 57, 56 printed on page, for the sensor wiring and pdf page 64, 63 printed on page, for the pin numbering on the plug, T2)

http://www.cannell.co.uk/Workshop_Manual_Toyota/MR2_ELECTRICALWIRINGDIAGRAMS.PDF

Pin 1 you say is signal ground is that pin 24 on the ecu (atom)?

I have shielded cable on the speed wires should that go to pin 7 or is it not needed?

Thanks