New to tuning, chasing a stutter/hesitation

Discussion of tuning specific to MAZDASPEED6/MAZDASPEED Atenza/Mazda 6 MPS vehicles
BrownDog185
Posts: 10
Joined: September 28th, 2020, 5:08 pm

New to tuning, chasing a stutter/hesitation

Post by BrownDog185 »

hey guys, im relatively new to tuning and could use some help

completely stock Mazda 6 MPS [except ive blocked the BOV off]

having some issues with the OTS maps, they all seem to have various amounts of Missfire/hesitation/stutter around the 3000-4500 rpm range
car is freshly serviced, and had been flash tuned by the previous owner and the hesitation was not present
the dyno printout does show some serious knock retard on the factory tune though

The 91us/93eu with CAI tune is the best working so far, with only minor stutters in the same rpm range

what should i start logging??
mituc
VersaTuner guru
Posts: 1324
Joined: December 17th, 2011, 2:47 pm
Location: Iasi/Romania

Re: New to tuning, chasing a stutter/hesitation

Post by mituc »

BrownDog185 wrote: September 28th, 2020, 5:15 pm completely stock Mazda 6 MPS [except ive blocked the BOV off]

If you have an aftermarket BOV (even though you say the car is 100% stock) then I can suppose you blocked the vent-to-atmosphere port and returned to its normal operation as a BPV (ByPass Valve or Recirculation Valve).

If the BPV (not BOV) is also stock and you blocked it then there's your hesitation problem.
2008 Cosmic Blue Mazda 3MPS
Built engine + WMI + GTX3071 gen2, ~509BHP @34PSI
2008 Icy Blue Mazda CX7
Stock engine and exhaust (YES!!), JBR3" + GTX2867 gen2 + Autotech HPFP, self-tuned to 330-ish BHP
BrownDog185
Posts: 10
Joined: September 28th, 2020, 5:08 pm

Re: New to tuning, chasing a stutter/hesitation

Post by BrownDog185 »

mituc wrote: September 29th, 2020, 7:41 am
BrownDog185 wrote: September 28th, 2020, 5:15 pm completely stock Mazda 6 MPS [except ive blocked the BOV off]

If you have an aftermarket BOV (even though you say the car is 100% stock) then I can suppose you blocked the vent-to-atmosphere port and returned to its normal operation as a BPV (ByPass Valve or Recirculation Valve).

If the BPV (not BOV) is also stock and you blocked it then there's your hesitation problem.
ahh you would think so, but it was there before i blocked it off.
probly should have mentioned it

it also gets worse after using flat shift or launch control and the second it hits 4500 rpm it run flawlessly
BrownDog185
Posts: 10
Joined: September 28th, 2020, 5:08 pm

Re: New to tuning, chasing a stutter/hesitation

Post by BrownDog185 »

or if someone can tell me how to extract the tune from the backup i can import that tune into VT
mituc
VersaTuner guru
Posts: 1324
Joined: December 17th, 2011, 2:47 pm
Location: Iasi/Romania

Re: New to tuning, chasing a stutter/hesitation

Post by mituc »

BrownDog185 wrote: September 29th, 2020, 12:49 pm ahh you would think so, but it was there before i blocked it off.
probly should have mentioned it
If it was there before then it's worse now.

I had something similar on my CX7 and I managed to tune it off, however, it comes back intermittently when it's cold outside (usually way below freezing) but barely feeling it.

So put the BPV back on, it's there for a very good reason which should not be ignored. Then try to:
- determine when it manifests itself (cold, hot, just started the car for less than X minutes, and so on);
- find a way to reproduce it;
- log it and post a log here in .csv format.

You cannot extract the tune from your car, not with the Versatuner software anyway. But you can write a 100% stock tune with Versatuner, or an OTS (off-the-shelf) tune from the tune repository.
2008 Cosmic Blue Mazda 3MPS
Built engine + WMI + GTX3071 gen2, ~509BHP @34PSI
2008 Icy Blue Mazda CX7
Stock engine and exhaust (YES!!), JBR3" + GTX2867 gen2 + Autotech HPFP, self-tuned to 330-ish BHP
BrownDog185
Posts: 10
Joined: September 28th, 2020, 5:08 pm

Re: New to tuning, chasing a stutter/hesitation

Post by BrownDog185 »

what should i log exactly

i can reproduce this at will, first pull in 4th not a problem, any following pulls it happens
however if i cruise around for a little while and go again it repeats; first pull its fine, change gear or slow down and go again and problem appears.
dosent matter if partial throttle or WOT, can have a minor stutter after opening throttle again to cruise
i dont think its there when its cold [car warms up before i get out of my estate]

am wondering if this related to BAT or IAT

its funny, i tried using a factory tune and its there aswell, pretty subtle but its there
the custom flash tune that came on the car is the only one that doesnt do this

problem is literally the same BPV or no BPV [unblocked it for now]
mituc
VersaTuner guru
Posts: 1324
Joined: December 17th, 2011, 2:47 pm
Location: Iasi/Romania

Re: New to tuning, chasing a stutter/hesitation

Post by mituc »

Download this logging preset and use it to take a log:
https://www.dropbox.com/s/hmw8hc97atbqp ... vtpre?dl=0
2008 Cosmic Blue Mazda 3MPS
Built engine + WMI + GTX3071 gen2, ~509BHP @34PSI
2008 Icy Blue Mazda CX7
Stock engine and exhaust (YES!!), JBR3" + GTX2867 gen2 + Autotech HPFP, self-tuned to 330-ish BHP
BrownDog185
Posts: 10
Joined: September 28th, 2020, 5:08 pm

Re: New to tuning, chasing a stutter/hesitation

Post by BrownDog185 »

will do

in the mean time ive got this one i just did
it was pretty good today weirdly....

there is a few though, pretty solid miss as it approaches 3000rpm, or applying any load after coasting
Attachments
VersaTuner Logs.zip
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mituc
VersaTuner guru
Posts: 1324
Joined: December 17th, 2011, 2:47 pm
Location: Iasi/Romania

Re: New to tuning, chasing a stutter/hesitation

Post by mituc »

Convert to .csv before posting the logs on the forum. Those who can help you don't necessarily have the MS6/6MPS specific version of versatuner and will not be able to import these logs.
2008 Cosmic Blue Mazda 3MPS
Built engine + WMI + GTX3071 gen2, ~509BHP @34PSI
2008 Icy Blue Mazda CX7
Stock engine and exhaust (YES!!), JBR3" + GTX2867 gen2 + Autotech HPFP, self-tuned to 330-ish BHP
mituc
VersaTuner guru
Posts: 1324
Joined: December 17th, 2011, 2:47 pm
Location: Iasi/Romania

Re: New to tuning, chasing a stutter/hesitation

Post by mituc »

Ok, so in your log none of the parameters you logged can be used to figure out what's going on. Please use the logging preset I've sent you.
2008 Cosmic Blue Mazda 3MPS
Built engine + WMI + GTX3071 gen2, ~509BHP @34PSI
2008 Icy Blue Mazda CX7
Stock engine and exhaust (YES!!), JBR3" + GTX2867 gen2 + Autotech HPFP, self-tuned to 330-ish BHP
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