MP3 ecu on the way, some questions?

V
2003 Protege DX 5MT
Hi all and yes I have searched this forum before posting this thread;

I have researched and ordered a 2001 Mazda Protege MP3 ecu / pcm (computer) part number FS9N-18-881 followed by either a B or C, the one I have on the way is from a 2001 mp3 Vivid Yellow and from what I understand it is one of about 1500-2500 Mazda Protege MP3's ever made.

My question is concerning the VTCS system. From my knowledge, the 2001 Protege MP3 never had VTCS in the intake manifold. Would I be ok with swapping the MP3 ECU into my 2003 2.0L Protege without doing the VTCS removal?

I did a pre test today starting the 03 protege in 40 degree weather. The VTCS was on (visually inspected before startup) the actuator closest to head / by fuel injectors was closed then open after the engine was warm. When the engine was cold i unplugged the green vacuum switch to the left on top of the intake manifold and the arm closed so i confirmed it is VTCS. So from my test, I am thinking that the VTCS is by default normally open and the MP3 ecu won't see it and keep it open by default.

My question is will I be ok after plugging in the mp3 ecu and not having done any kind of vtcs delete?

Thanks
Thomas
 
Last edited:

grffn

Contributor
V
'02 P5
Yes, you just won't utilize it's full potential; still quite a nice improvement anyway.
Some people elect to remove the butterfly flaps. I haven't done it as it seems like a bit of work I'm not looking to do.

Otherwise I've personally been running the MP3 ecu without VTCS removal and no problems.
Make sure you run high octane gas now that you have that ECU, and disconnect battery for a few mins then reconnect to relearn ECU process. Will likely run sluggish first 100 miles or so until it adjusts.
 
V
2003 Protege DX 5MT
Yes, you just won't utilize it's full potential; still quite a nice improvement anyway.
Some people elect to remove the butterfly flaps. I haven't done it as it seems like a bit of work I'm not looking to do.

Otherwise I've personally been running the MP3 ecu without VTCS removal and no problems.
Make sure you run high octane gas now that you have that ECU, and disconnect battery for a few mins then reconnect to relearn ECU process. Will likely run sluggish first 100 miles or so until it adjusts.

Is this ecu reset a frequently needed thing I have to do with my new ecu? I have done this before to clear CEL or when working on cars in the past.
 
V
2003 Protege DX 5MT
Update: I swapped out the mp3 ecu with no modifications to VTCS and no problems.

My protege definitely wants to rev higher when accelerating, 2nd gear pulls a lot harder, and it almost opened up a new power band for the car @ around 4000 rpm. Acceleration in 3rd through 5th gear is definitely noticeable. I have put modifications on several of my cars and this ecu swap-tune is definitely worth it.

All proteges should have come stock with this tune.
 

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