rapid boost fluctuations!? HELP - Subaru WRX Forum
  • 1 Post By pjkatz04
  • 1 Post By arcticscythe
LinkBack Thread Tools Display Modes
post #1 of 5 Old 03-07-2014, 09:52 PM Thread Starter
WRXtuners Member
Join Date: Mar 2014
Location: New York
Posts: 5
Exclamation rapid boost fluctuations!? HELP

Hey I just bought an 02 wrx with a vf48, sti tmic, sti injectors, 3inch castles turbo back exhaust, tuned by efi logics. Anytime it boosts Past 10psi the car stutters rapidly and doesn't pull. The gauge goes crazy between 10-15psi. The air/fuel gauge drops to around 11:1. If I keep it under 10psi its fine and I can rev it out slowly all the way. No clue what this could be. Maybe has to do with the tune? Previous owner says its because of the cold but that doesn't make sense to me. Help please
tommygunn is offline  
Sponsored Links
post #2 of 5 Old 03-07-2014, 11:22 PM
boo-key's Avatar
Join Date: Dec 2008
Location: Tennessee
Posts: 1,781
Images: 6
Efi logics has a good tuner if mike tuned it. Sounds more like a mechanical problem.

06' wrx tr
Phatbotti tuned!
boo-key is offline  
post #3 of 5 Old 07-25-2014, 10:18 PM
WRXtuners Member
Join Date: Jul 2014
Posts: 10
Possibly could be fuel problem as well
kirby32rex is offline  
Sponsored Links
post #4 of 5 Old 07-28-2014, 08:33 AM
WRXtuners Member
pjkatz04's Avatar
Join Date: Jul 2012
Location: New York
Posts: 168
im by no means an expert, but I do know that my '12 behaved the same way immediately after I flashed w AP w tune for the cobb intake, and hadn't actually put the intake on yet. Once I got home and put the intake on, it behaved normally again.

From that one experience, I'd guess that the tune isn't correct for the hardware. Maybe previous owner took off the good sh*t and put junk on/old stuff for the sale and didn't spend the expense of getting it re-tuned.
boo-key likes this.
pjkatz04 is offline  
post #5 of 5 Old 07-28-2014, 02:23 PM
WRXtuners Member
arcticscythe's Avatar
Join Date: Dec 2013
Location: California
Posts: 1,540
Sounds like it could be a MAF issue, If the ECU is seeing too much or not enough air and dropping AFR to 11 and bouncing around under WOT then there's definitely something going on with that tune or your MAF. You can try Cleaning your MAF with some MAF cleaner, Be really careful not to handle it by anything other than the connector and be sure it s completely air dried before re-installing. If that doesn't fix the issue then my guess is that the previous owner added or swapped parts without the tune and just drove it like that. Ive seen too many drivers with "performance" parts with not tune making the rest of the tuning community look bad. Your tuner should be able to load on a limp home tune just to test for other issues and while its there they can do a dyno tune and get you running with the full potential of those parts.
thekamikaze kid likes this.

- Jason
Slow is Smooth > Smooth is Fast
arcticscythe is offline  

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome