Syvecs Forums

Hi All,

Been out the game for a few years, but am now looking to get my MR2 running again.

I am rewiring the engine bay from scratch, using none of the stock wires (they've already been removed in a permanent method involving sharp tools).

Most of it seems pretty straight forward, but I have a question about the IACV/TBV.

The MR2 TBV has three wires, RSC, RSO, and Gnd, which as I understand it, is for opening and closing the valve.

The question is, my Syvecs config only has one output assigned to the TBV, should this connect to RSC or RSO, and, if only one is used, do I need the other wire?

I'm sure there will be more questions once I apply power to the system and it doesn't work

I knew there was another question:

So I know the firing order for the MR2 is 1-3-4-2

And I know that the cylinders are (when looking at the engine from the rear) 4-3-2-1

Does this mean that, when considering the Syvecs outputs as Cyl 1 - Cyl 2 - Cyl 3 - Cyl 4, the wiring should go to the coils on the physical cylinders like this?

Cyl 1 = 1 (R)
Cyl 2 = 4 (L)
Cyl 3 = 3 (Mid L)
Cyl 4 = 2 (Mid R)

just wire cyl1 to output 1, cyl2 to output 2, etc etc etc. Same for injectors and coils

You set the firing order in the software.

Thanks for the reply, so, just to clarify, my current Syvecs config has the firing order set to 1-3-4-2 and the view looks like this:



My Pin config looks like this:



In the first image, at the bottom, do the green numbers correlate with the pin config?

So, in my case, I wire FUEL 01 to the right most cylinder, FUEL 02 to the left most cylinder and so on?

shmed wrote: Sat Sep 21, 2024 1:28 pm
So, in my case, I wire FUEL 01 to the right most cylinder, FUEL 02 to the left most cylinder and so on?

That makes no sense.

Why would cyl1 and 2 be at extreme ends of an inline engine ? They are beside each other. 1, 2, 3, 4. Unless it's some very very weird engine you have

It's absolutely simple.

Wire cylinder 1 to output 1
Wire cylinder 2 to output 2. And so on, and so on.

Sorry, I'm sure this is simpler than I am making it

I think I now understand what you are saying though.

My engine is numbered right to left so, when looking at the engine they are:

4-3-2-1

So I wire them in that order so FUEL 1 goes to the right most cylinder, and I just work along right to left, then the ECU does the rest as it knows to fire them in the order 1-3-4-2.

Sorry, I think I was overcomplicating it!

The MR2 TBV has three wires, RSC, RSO, and Gnd, which as I understand it, is for opening and closing the valve.

I don't suppose you can help with this one can you?

I also have a new question regarding the CAM pos. sensor as the car has a COP conversion (I think from a 1ZZ). There is, what I believe to be, a CAM sensor where the dizzy used to be. It has four wires, but I can't find out any info as to what these might do.

The ECU config only has 1 pin assigned to CAM phase, so I am not sure what the others do.

I assume that they are like most other sensors with a Ref/Signal/Gnd setup. Just not sure what the fourth wire might be.

shmed wrote: Sat Sep 21, 2024 2:46 pm

The MR2 TBV has three wires, RSC, RSO, and Gnd, which as I understand it, is for opening and closing the valve.

I don't suppose you can help with this one can you?

I also have a new question regarding the CAM pos. sensor as the car has a COP conversion (I think from a 1ZZ). There is, what I believe to be, a CAM sensor where the dizzy used to be. It has four wires, but I can't find out any info as to what these might do.

The ECU config only has 1 pin assigned to CAM phase, so I am not sure what the others do.

I assume that they are like most other sensors with a Ref/Signal/Gnd setup. Just not sure what the fourth wire might be.

You are best to investigate the wiring on the car that was working first, and then make changes.

I think the Toyota used a sensor on the cam/belt for all position data ? ie, rotational speed and cyl1 ID ? in lieu of a better system with a direct crank trigger with missing tooth etc ?

The wiring could be for "crank and cam" so to speak, or it could be a power supply. You need to look and see.

The ecu will only ever have 1 wire assigned to an input, for any input.

As for the idle, not sure. Some setups may just drive the valve in one direction instead of the factory two. But I'm not sure what your options are.

TBH I'd bin it and go DBW anyway

Is the car running Syvecs at the minute ? or a different ecu ?

Hi again,

The car has an S6 which was working fine until I got my hands on it.

I do still have the old ECU harness so I can probably reverse engineer it based on the wire colours.

I never considered DBW, but an now looking into it.

In terms of the cam position sensor, the engine is a 5S-GTE so it never had one as stock. That's what makes it harder for me to research which wires go where.

I feel like such a tw@

I have assumed that the cam position sensor is in the silver cap that is where the dizzy used to be. I am now unsure as it looks very much like the dizzy deletion cap sold online. This suggests that the four wire connector was actually for the dizzy and may have nothing to do with the cam position sensor whatsoever!

Reckon I will take the cap off and see what is inside.