Just got the parts for a MS3X
 

Per the title, just got the parts to do a MS3X via the trubokitty instructions...

Picking up a set of ITB's this weekend with a plenum, planning on getting that all hooked up and then deciding if I want to turbo them or build a high comp NA; will keep this updated as I go along...

Are there any small "things" I should know about doing a MS3X to my NB1 platform? I think that I will want to go VVT later on, not sure how difficult that is - I was just going to solder the resistor in place on the back and leave it there until I get a new head, but, I'm unsure how that would work with the NB1 ECU connection...

The MS3X shouldn't care if nothing is wired up to its VVT pin.

I was more curious how that would work into the NB1 vs NB2 ECU connection, as I was under the impression that the plugs and actual wiring on the car side were different

Unless you're switching chassis to an NB2 it doesn't matter. You just have to add a wire for VVT separately outside the harness.

Makes sense

wire VVT to a spare unsued pin in the engine bay. Connect your vvt solenoid there later. Like the EGR BOOST solenoid valve, or Purge Canister Valve or something. You can use those same connectors to give your vvt solenoid power as well...


this will help you: http://www.mellens.net/mazda/mazda_m...999_wiring.pdf

I'm interested in doing something similar with my EGR connector. Is there a known P/n for the connector that is normally mounted to the valve?
I could just buy a random 4 pin automotive connector as well.

Is the 12V that goes to the EGR from the ECU, or otherwise supplied?

see the connector witch hunt thread?

almost all power in the engine bay is running off the same white/red wire...

just finished putting it together and wiring up the harness, have it powered off the car and I'm flashing it right now... Going to try and get it running with the stock intake tomorrow, then when my TPS & filters come on Friday, drop in the AE101 ITB's with the T3 manifold & stacks.

Thanks for the walkthrough on trubokitty :)

Fuel pump primes, engine cranks, all sparks tested to be good.

Only issue is, I'm not seeing any RPM when cranking!

I have the jumpers per your instructions, and I have triple checked the three trimpots and even messed around with the 7.5 turn one a bit...

However - I just noticed, https://trubokitty.com/assets/images/ms3x_expander.png shows a ground connection from X - 32 to the main 37 pin d sub connector.

I didn't do that - I'm assuming that that would cause this issue? Can anyone explain what is meant by this, hopefully with a picture? Thanks much!

do a composite log so we can see if it's the crank or cam sensor that's not inputting. (diagnostics tab, save to file, crank for a good 15-20 sec to get a reading, go WOT when you crank so no fuel is injected)

Odd! After cranking it for 15-20 seconds, I did get a very short signal...

I'm thinking this means its probably the VR trimpots? Is there a better way to do it than counting turns? The "clutch" on these don't click so I don't know when it is all the way left, I've just been spinning it a ton, getting it vertically aligned and counting half turns... I was seeing that another way is to adjust for minimal voltage off of the top end (one facing the center of the board) of R54 next to the trimpot, using some kind of a ground as the negative. Is that true?

looks like you were getting the cam signal, but not the crank (I had to look at the log in excel here).

For NBs, I tend to just spin the R56 exactly 8 turns CW (resets at 12 turns CCW). and R11 4 turns CW, with R32 backed out completely (at least 6 full turns CCW).

Whenever I'd try setting these with specific voltages, I kept getting reports of issues.


not following this. pin 32 of the expander is the Cam Sensor Input.

Ok - so this is likely a trimpot issue then? Any particular solder or harness connections I should check? I tested for closed on each harness cable and it was fine, but I don't know if a weak signal could cause it too.

Thanks Braineack, Ill check trimpots again when I get home

I've adjusted the trimpots multiple times now, going up and down inbetween cranks checking for RPM... Nothing - is there anything else I can check for this?

pics of board? triple check harness.

Ill take picture of board when I get home and check harness for continuity again... All traces and pads are good, I believe I have all components in place

Every harness connection tested good... The vrout, vrin, tsel and tachsel are jumped on the bottom. Here are some pictures... Going back through everything right now.
Jumper 7 on the expansion board should be removed, right?

https://cimg4.ibsrv.net/gimg/www.mia...74cb828e4c.jpg
https://cimg7.ibsrv.net/gimg/www.mia...89ed29adaa.jpg
https://cimg3.ibsrv.net/gimg/www.mia...2a253a3ef6.jpg
https://cimg0.ibsrv.net/gimg/www.mia...8f88709c77.jpg

the 1k resistor on r13. you need to cut it out from the hole and it needs to only connect down to the other resistor you have it bridged with.
the hole on the far side of that image is 5v. the resistor below is part of the crank signal input circuit. we just use that for a 5v pullup, to power the signal, through that 1k resistor.

youre also missing c31.

everything else seems good. the harness appears to have everything in the right spot.

edit; looking again it seems the pullup is okay?

The pullup is just going from the left side of r13 down to the right pad of the resistor below it... I moved it on to the pad instead of the resistor leg - didnt notice c31, hoping that makes a difference. Resoldering the vr jumpers on the bottom too