[Mazda Carnage]

Unrelated - you mentioned something previously about the way the boost solenoid is set up, and something about removing it to make the car continue to make more power at higher RPMs. Maybe I was misunderstanding. But are you able to explain that more at all?
In other words -
1. How should the turbo be set up to run correctly/safely with the solenoid removed
2. Should I leave the solenoid in place to make sure the car is running properly first before playing around with that sort of stuff?

Removing it gives the car a steady power band, the wastegate is about 7psi, the solenoids opens in mid RPM and acts as a boost controller raising mid range boost to about 8.5psi, when it shuts at higher rpm the entire power band falls with it.
This can be accomplished by simply unplugging the solenoid valve at the wire harness however this will reduce peak engine torque because max boost will be lower (mid rpm) but will give the engine a steady power band.
Of course most people install a chip and boost controller and run 15psi on the factory turbo while dreaming of upgrading the turbo.
I am cutting you some slack because your going from N/A tuned to turbo and although it's a small step it's in the right direction.

What I recommend for you is that you leave the solenoid where it is and plumb the hoses like factory.
Unplug the solenoid from the factory engine harness and run 12V from a relay controlled by a toggle switch to the solenoid valve (always use switched 12V to activate the relays coil).
Loosen the locking nut on the solenoid valve and unscrew the adjustment stud 1/2 turn, lock the nut.
Drive the car with the boost solenoid turned on and repeat the process until you see 10psi in higher rpm 4th gear on a boost gauge.

You will have two stages of boost, 7psi and 10psi. I say always leave the toggle switch on unless it snows in Australia.
You can run up to 12psi before hitting boost cut, boost cut is decided by the air flow meter flaps travel so how much air the engine gets not how much boost pressure is in the manifold, 10psi should be far enough away from 12 that small boost spikes wont trigger boost cut.

 

[HL-240]

Yeah ok I think that makes sense. I think for now I'll just get it running on the stock setup and maybe then look at something like you described.
The reason I don't want to run too much boost at this stage is because I have the NA gearbox, if I can find a turbo gearbox later on then I might look at running more power.

Also, I have a couple of old coolant temp gauges lying around and I was thinking of using one as an oil temp gauge. Any suggestions of where the best place to locate the sender would be?

 

[HL-240]

@Mazda Carnage do you have any suggestions of websites that might have wiring diagrams for the B spec 626/MX6? I've tried searching but havne't been able to find much.

We installed the wiring from the MX6 into the 626 today, the main issues seem to be the following:

1. There are 2 'spare' white plugs at the ECU, that don't plug anywhere and were not on the old NA harness.
I have a feeling that one plugs into a relay that I forgot to get from the MX6 tomorrow and the other I think is the same spare plug that this guy had
Mazda 626 Turbo Conversion, Plz help
so I might need to do some colour matching.
I'm hoping/guessing that the wires will all be the same, but the mx6 had them split over 2 plugs as opposed to the 626 having them all in one plug.
This is the spare plug:

2. Where the harness comes through the firewall on the passenger side (or what would be the drivers side for LHD cars) there is one plug that was the same on the 626 NA harness which plugs in fine, but two extra/spare plugs.
Looking at where these plug into on the MX6, one looks like it might be go to door wiring or something like that, but the other looks like it goes into the dash harness.
I'm not sure what to do about that one except potentially check the wiring as with the ECU ones above, or maybe just see if the car runs after it's all back together and then see what systems don't work (eg lights or cluster or whatever).

Big spare plug from the LHS firewall ^


Aside from that there were some other issues eg headlight connectors being different and wiper motor connector being different but these should be easy enough to sort.

One other thing I'm not sure about, there's this big round connector which on the MX6 went down into the steering rack. I don't think the 626 has this but I'll need to double check tomorrow. the workshop manual lists a steering operation switch as part of the 'idle control system' so maybe the 626 doesn't have this switch?

 

[Mazda Carnage]

None of your recent pictures are showing up.

The steering rack connector isn't an issue, the turbo models have different steering control. Yours will work as it did.

I don't know where to find the factory wiring diagrams for free in pdf for for Bspec F2/F2T

There is some stuff here:
Mazda 626 - Manuals - Mazda

Index of /ftp-uploads/626

Try searching for PDF's
I do see some original factory wiring manuals for sale online.

 

[HL-240]

See if this works:

ECU spare connector

LHS firewall spare connector

I double checked and yes the 626 does have a connector from the steering rack but a different plug. Guess I can just swap the plugs over.

Also a question about the rear main seal, do you think it's ok just to replace the seal itself and not the gasket for the rear housing that the seal is part of? Only reason for this is that to remove the housing I would have to redo part of the oil pan seal and I'd then be worried about leaks from the oil pan.

 

[Mazda Carnage]

Those pictures worked.

Looking at the connectors from the MX6 that have no place to connect in the car, I would look at the rear/door connections at the dash and see if they connect to the mx6 dash harnesses and just swap harnesses.

You can pull the rear main housing from the block and just redo the seem of the splash tray and rear main housing with gasket maker.

 

[HL-240]

, I would look at the rear/door connections at the dash and see if they connect to the mx6 dash harnesses and just swap harnesses.

Sorry what do you mean by this? I know they connect to the mx6 dash harness because they came out of the mx6 itself. But I'd prefer not to have to pull the whole dash out just to solve 2 or 3 plugs.

You can pull the rear main housing from the block and just redo the seem of the splash tray and rear main housing with gasket maker.

I know I can do this, but it would be a bit of a risk as there would no longer be a continuous RTV gasket (i.e. there would be 2 joins) so a bit more chance to leak.
I guess the question is whether you have ever seen that rear main seal housing gasket leak? If it's only a very small chance then I'll leave it but if it's common then I'll replace it

 

[Mazda Carnage]

Sorry what do you mean by this? I know they connect to the mx6 dash harness because they came out of the mx6 itself. But I'd prefer not to have to pull the whole dash out just to solve 2 or 3 plugs.



I know I can do this, but it would be a bit of a risk as there would no longer be a continuous RTV gasket (i.e. there would be 2 joins) so a bit more chance to leak.
I guess the question is whether you have ever seen that rear main seal housing gasket leak? If it's only a very small chance then I'll leave it but if it's common then I'll replace it

Personally I would rather spend 4 hours swapping harnesses than 4days pinning and wiring 2 or 3 connectors.
The F2 dash is really easy to remove, it's bolted into the car, no one time use clips like the shit built today.
For the car I am building I need to use the dash out of my 1988 mx6 GT because the vent area is cut up for the gauge bezel where the oscillating vents where. The wiring will come from a 5door a spec dash (stored improperly has a crease on the top) I have in the basement. So I have to pull the mx6 dash and bring it home, Put the 5door wiring in it. Then take the blue 626dx dash I have stored and put the mx6 gt harness in it and reinstall it in the MX6GT. Then I will have a dash to but in the 626GT I am building. This will all be done in one day (provided I can fit the dashes in the car I am driving).

The rear main seal housing gasket is not a common fail point but accessing it is a pain in the ass on a running car. You have access to it now, RVT is liquid and there are only 2 oil pan bolts at the seal housing, with all the other oil pan bolts still on the motor it would be quite easy to pull the housing off and reapply RVT to it and have a perfectly sealed oil pan.