[SOLVED] Not building boost & stuck in launch control in all gears, please help

slo.ms3

slo.ms3

Greenie N00B Member
Hey guys, A while back I bought this 2012 Mazdaspeed 3 with a few mods: Catback exhaust, Intake, and BOV 50/50 with Autotech hpfp internals. 5 months ago I was driving and the car just died on me. I wasn't pushing it or anything. It didn't want to start. Ended up towing it home and the motor was good, with no oil leaks or coolant leaks. The first issue I had was a cylinder 4 misfire but I cleared it and didn't think too much of it. I have changed the spark plugs, new Corksport Throttlebody, new MAF sensor, HPFP e85 Safe rebuild kit, primary 02 sensor, and nothing has worked. I gave it to Mazda and they had me wait 5 months for a new PCM and charged me 2k for no reason. They recommended changing the harness and o2. Attached is a datalog of me driving around. about to give up on this thing. If you guys/gals can help that would mean alot.
 

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What intake are you running? Plugs are gapped at .026-.028" right? Is that stratified tune for your CS throttle body? While corksport says a tune isn't needed for it, they do recommend it as would I.

Have you tested your PRV? Because looking at your fuel pressure it's low.
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Also ensure that ground by the hpfp is clean and tight otherwise you have weird issues, also ensure that the electrical connector on the spill valve is seated properly and not loose especially after recently rebuilding the pump
 
so I just went on the first drive and the problem went away after damn near half a year of repairs. I am running a corksport stage 2 short ram with a 3'' K&N intake & yes NGK plugs are gapped at 0.27I was driving it around and it made a weird ticking noise. I'm praying it's not my chain guides. I'll open up my valve cover tomorrow and find out. I am currently running a Cobb OTS stage 1 tune. I know it's shitty but that's what it had when I bought the car. I already hit up Justin @ Freektune to see what he thinks. I'll clean up the hpfp ground since I've heard that did it for a lot of people. However, it's still not 100 percent fixed since the problem is coming back intermittently.
 
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I took a look at my injectors and it turns out one of them was loose. I tightened it up and it drove fine. The issue I am now having is that it's not pushing more than 10 pounds of boost. The only plus side is that the rpm limiter I had is gone and I can drive it at least,. The car itself is running way smoother. Could it be my boost controller?
 
Okay so things that pop out to me right away-

-Boost leak test - have you done it?
-LTFT - what is it at idle fully warmed up? What is it under normal driving conditions when the car is fully warmed up?
-Don't get try to romp on it until Justin takes a look at some of your logs if you have already purchased. If you haven't reached out to Justin yet, I wouldn't purchase until you run through some more basic troubleshooting.
-Your intake is a 3" intake. Anything over the stock size 2.5" requires a MAF cal, and your car is having a hard time understanding air flow as a result of your incorrect tune for that intake size. If you have your stock intake, put that back on until you order a tune.
 
I haven't done a boost leak-down test yet. I don't know my LTFT at idle fully warmed up yet. Normal driving conditions are clear weather around 70 degrees Fahrenheit. Noted, I won't push it till it's 100%. Can I just slap on a 2.5-inch intake and call it a day?, since I don't have my stock intake.

For some odd reason, my AFRs are stuck at 14.85. I've already replaced my o2 sensor and it's still stuck. I've uninstalled and re-installed the AP to see a difference and it's still there. I've also tried using the launch pro scanner and it's even stuck on the launch scanner. Do you think this is something the dealer did when they installed the new PCM?

I'll try to do a boost leak down test ASAP
 
If the age is stuck you have a problem with the o2 sensor. Which one did you change the upper one is the one that impacts the tune. Check the plug wiring at the same time
 

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Ahh man, I'll try that sensor out and see. Here is a recent datalog of me driving around. Can't pass 10 psi boost and it starts cutting up at the top end. I usually get 16-18 psi with stock k04 before this problem. This was after cleaning the hpfp internals + rebuild kit. I'm also getting a battery light code only under load. I'm suspecting a bad harness/connector at this point.
 

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Update, I fixed the problem by changing the engine harness. This MS3 had a front collision with the previous owner and I assume the harness was soldered back together. A new Harness did the trick! I'm having issues with the CS ThrottleBody however, there is a recall on it since it's defective. I already have a new one on the way. Thanks, guys and gals
 
Happy to hear you got it sorted, pesky previous owners.

Sorry about CS TB luck, someone in shoutbox was saying they're on their 3rd one now.
 
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