MS3 PCM fault?

[Tyler Young]

My bad Johnny lol

The codes I throw the most, whenever I actually can read them, are for the map, rich ignition, random misfire (less frequent). When I print out the codes at AutoZone they recommend I replace my evap solenoid

So does AP come with something? Kinda like Cobb accessport?

 

[jsmith]

You are far beyond what Autozone can diagnose.

 

[Tyler Young]

Lmao oh I know but I haven't bought an obd2 reader yet, saving up

 

[jsmith]

An access port, instead of an obd2 reader, would be a better solution.

It would read codes, datalog aaaand let you flash an appropriate map for your mods.

 

[jcolton]

So I bought a 2012 about 9 months ago from a dealer,......
For the past few weeks I've been chasing an electrical fault/ghost vacuum leak that, at any given time, causes my ms3 to read full boost, then drop into limp mode.

I had this exact problem and it ended up being the connectors inside the end of the MAP harness. During previous troubleshooting, I was jamming bits of wire like a dumbass into the end of the plug to test for continuity/resistance to pcm end of harness and in doing so it spreads the terminal(s) out enough that you're losing probably the ground or sensor wire connection erratically from the MAP sensor to the PCM. Making your boost pressure show up at the PCM as the maximum pressure value of the sensor. You might get lucky and find an oem harness for cheapish or you could go with something like this https://edgeautosport.com/bosch-4-way-sealed-plug-bsk-connector-pigtail-for-bosch-map-sensor/.

edit:
"The only thing that confused me is the boost gauge shows a constant vacuum leak."
Definitely pick up an AccessPort and make sure that your pcm is actually flashed to read the correct map sensor value (close to 0 at KOEO). With that modlist you're going to want one anyways

Good luck I hope that helps!

 

[Tyler Young]

An access port, instead of an obd2 reader, would be a better solution.

It would read codes, datalog aaaand let you flash an appropriate map for your mods.

Ya but it'd take me forever to save up $650 to get 1

I had this exact problem and it ended up being the connectors inside the end of the MAP harness. During previous troubleshooting, I was jamming bits of wire like a dumbass into the end of the plug to test for continuity/resistance to pcm end of harness and in doing so it spreads the terminal(s) out enough that you're losing probably the ground or sensor wire connection erratically from the MAP sensor to the PCM. Making your boost pressure show up at the PCM as the maximum pressure value of the sensor. You might get lucky and find an oem harness for cheapish or you could go with something like this https://edgeautosport.com/bosch-4-way-sealed-plug-bsk-connector-pigtail-for-bosch-map-sensor/.

edit:
"The only thing that confused me is the boost gauge shows a constant vacuum leak."
Definitely pick up an AccessPort and make sure that your pcm is actually flashed to read the correct map sensor value (close to 0 at KOEO). With that modlist you're going to want one anyways

Good luck I hope that helps!

I'll definitely have to check out that harness, cuz just from the looks of it homeboy rewrapped the entire wiring harness. Not the worst rewrap I've ever seen but definitely rushed

 

[jsmith]

Ya but it'd take me forever to save up $650 to get 1

Buy used perhaps?

 

[SharksInSpace]

Ya but it'd take me forever to save up $650 to get 1

Start saving. You NEED a tuning solution with that hardware setup for the car to run right. You really shouldn't even be driving it until then, tbh.

 

[Tyler Young]

Start saving. You NEED a tuning solution with that hardware setup for the car to run right. You really shouldn't even be driving it until then, tbh.

That's why I tried a bunch of times to get in contact with the first owner, cuz I've had it running like this for a little under a year. I've owned and worked on cars for the better part of a decade but this is my first tuner. But I'll try and find a used accessport, I looked when I first found out about em, couldn't find any but I suppose it's time to look again

If anybody that's in this thread has our knows anyone with either a laptop with W10 or an accessport, lemme know

 

[Easter Bunny]

Ya but it'd take me forever to save up $650 to get 1

Then you can't afford to keep driving this car. Find $600 for an ap or find $4000 for a new motor

 

[Tyler Young]

$200 or less for a laptop and $300 for obd2 cable and versatuner. I'm just now finding out exactly what I need to do, that was the point of logging onto this forum. I don't hammer it because I know if there's too much or too little fuel I could blow a gasket, throw a rod or destroy half my sensors. I get the importance of this, shit, I change my oil every 2k or so just to be sure cuz I can hear the difference at 3k

I make pretty good money, but not enough to just pull a half bill out my ass Willy Billy ya know. That's why I got a Ms3 and not a GTR

 

[Easter Bunny]

You could start saving money by not wasting two thirds or more of your oil life.

 

[SharksInSpace]

If you absolutely cannot avoid driving it, then just take it as easy as possible with trying to stay out of boost, etc. If you are in a position to be able to park it, that would be best for the time being.

I'm not gonna judge you on your financial situation or choices, but we tend to not sugarcoat things around here so do be prepared to have it told to you straight with no frills. Ultimately, our goal IS to preserve these cars and help people keep/get them running correctly for many miles to come.

 

[Tyler Young]

I wasn't trying to come across.. well, cross or anything. Y'all been helping me, but unfortunately it is more so a situation of I have to. I've got a 92 GMC 1500 that needs a new torque converter so that's currently a project in itself. Child support, on top of various other bills. Gets tough sometimes Ya know. But I'll be damned if I let this car go to shit ya know

You could start saving money by not wasting two thirds or more of your oil life.

Any other car I'd allow the oil to go for about 4k cuz I know the recommended 3k is a crock, for the most part but like I said this is my first boosted car so just leaning towards the side of caution tbh

 

[Tyler Young]

come to find out the 1st owner installed an EMUSA k04 spec turbo kit.... jesus..

 

[Cfoldone]

Just jumping in. A cheap diagnostic is eyeball all wiring, any breaks / flaws / insulation / jumpers not factory be suspicious. That's time consuming but.... Cheap. Diagnostic tools can point you to stuff. But eyeballs are excellent tools too. Anything not factory = suspect. That maybe a gross understatement. But in the end will need to be done.

 

[Tyler Young]

Ok, so it's about time for an update. The limp mode issue has become much more severe, everyday in fact. I now own the full version of VT, parked my MS3 at a safe location and will begin documenting everything i do from this point on. i have been doing nothing but watching videos and researching how to tune, although Mazda tuning/VT info is kinda hard to find, hence why I've chosen to document everything. if anybody could give me sort of advice it would be greatly appreciated.

 

[Tyler Young]

If I'm looking at this the right way, I have Auto tech HPFP internals. Can anybody confirm?

 

[Cfoldone]

Auto tech marking is covered by housing. I had to verify by taking spring off. Also to absolutely make sure was clean and not scored. Was a happy find that YES previous owner had done something right. The green line kinda shows how housing covers markings... honestly the exposed face flat doesn't look machined/lapped flat enough...
Sorry not much more to say yea, nay..

 

[Awafrican]

@Tyler Young as the post above said you gotta take that spring off to tell