[Longboarder]

So I'm still on the stock plugs now with over 30,000 miles and I've been modded since the day I bought the car with 7 miles on it. Very recently I started misfiring. Started with cyl 1, and now (after 2-3 weeks, I'm misfiring cyls 1, 5 and 6 intermittantly. Going to buy plugs today and hopefully that will cure the misfires. I did a log to see the effect of the misfires at WOT, if any.

This is a data log from a dead stop on a slight incline at 800 ft altitute. My boost curve has been modified in an attempt to remain at 13-14psi up to 4,000 RPM and then ramp up to 17psi at 4,500 and taper to 15-16psi at redline (in an attempt to maximize traction from a dead stop with 19" wheels). To my surprise, I hit 20psi briefly in 2nd gear and sustain 20psi in 3rd. AFR's are rich and timing low in 3rd gear, so I think acceleration is suffering....but I have no idea whether that has to do with the possible misfires (on this run) or the high boost/low timing. Will swap plugs and see if this does anything.

Curious if you guys with misfires are seeing anything strange in your data logs.

[cn555ic]

Whatever you did to those maps as for boost, I would get rid of them and load up the default boost mapping...You should not be sustaining 20 psi at all man..

[themyst]

PS: you're flatlining timing. Whatever happened to this being fixed? Every auto Procede log i've seen shows this flatlining behavior.

Back OT, if you misfired, your car would throw an SES light and the car wouldn't build any boost and sound like it has cams.

Time to change your plugs.

[Longboarder]

Originally Posted by themyst

PS: you're flatlining timing. Whatever happened to this being fixed? Every auto Procede log i've seen shows this flatlining behavior.

Back OT, if you misfired, your car would throw an SES light and the car wouldn't build any boost and sound like it has cams.

Time to change your plugs.

Hey Myst, yeah nothing I've done has fixed the timing flatline issue. It does recover, but is slow to do so. And yeah I have the SES light on and on cold starts, the car shakes and sounds like crap. Once warmed up it sounds fine though.

I'm going to lower my boost settings (0% and 100%) in the Procede after I get new plugs to see if by doing that it helps timing/AFR's.

[Longboarder]

Originally Posted by cn555ic

Whatever you did to those maps as for boost, I would get rid of them and load up the default boost mapping...You should not be sustaining 20 psi at all man..

Yeah good point, but the default maps target a higher boost profile, actually. I have lowered boost in the lower RPM range (below 4,500) to max at 14psi.

That's why this is strange. It's targeting 17 psi but hitting as high as 20.7. I thought maybe the misfire was to blame but I guess logically doesn't seem to make sense.

Misfires seem really common so maybe others are seeing this too.

[themyst]

Originally Posted by Longboarder

Hey Myst, yeah nothing I've done has fixed the timing flatline issue. It does recover, but is slow to do so. And yeah I have the SES light on and on cold starts, the car shakes and sounds like crap. Once warmed up it sounds fine though.

I'm going to lower my boost settings (0% and 100%) in the Procede after I get new plugs to see if by doing that it helps timing/AFR's.

Classic leaky injector symptoms. Find out which cylinder and get it swapped.

[Jeff@TopGearSolutions]

That may not be actual boost, is your throttle closing? You need to log CAN DBW. If your throttle closes it will induce an inflated reading of boost.

[Longboarder]

Originally Posted by Jeff@topgearsolutions

That may not be actual boost, is your throttle closing? You need to log CAN DBW. If your throttle closes it will induce an inflated reading of boost.

Not on this run, went WOT from a dead stop in 2nd gear and didn't lift off the accelerator as I paddle-shifted to 3rd gear.

[Longboarder]

Originally Posted by themyst

Classic leaky injector symptoms. Find out which cylinder and get it swapped.

That would suck. I'm getting misfires in 3 different cyls so really hoping it's just old dirty plugs.

[themyst]

Originally Posted by Longboarder

Not on this run, went WOT from a dead stop in 2nd gear and didn't lift off the accelerator as I paddle-shifted to 3rd gear.

the ECU may induce a throttle closure which can be logged with CAN DBW throttle monitor on the Procede; that's what he's talking about.

I highly doubt that is the case though because you are sustaining high boost post-shift. It's not uncommon for the Procede to show boost creep on long pulls due to EGTs rising under sustained load. I got plenty of logs showing similar behavior from when I ran the Procede.

[ttbmer]

R u still on stock DPs?
I don't think is easy on the turbos to push that much psi with stock Turbo Back Exhaust

[themyst]

Originally Posted by ttbmer

R u still on stock DPs?
I don't think is easy on the turbos to push that much psi with stock Turbo Back Exhaust

Look at his sig.

[Longboarder]

Originally Posted by ttbmer

R u still on stock DPs?
I don't think is easy on the turbos to push that much psi with stock Turbo Back Exhaust

Hey what's up David it's Adam. Did you get your car running right?

Check out this log - it's from my race against you at the airstrip event. My meth boiled over in the lines waiting forever on the hot taramac and so my meth didn't flow. Check out the 80c inlet temps. I think I could have ran faster! lol

[themyst]

Originally Posted by Longboarder

Hey what's up David it's Adam. Did you get your car running right?

Check out this log - it's from my race against you at the airstrip event. My meth boiled over in the lines waiting forever on the hot taramac and so my meth didn't flow. Check out the 80c inlet temps. I think I could have ran faster! lol

running negative timing like that is costing you a good 30 whp or so if not more. U gotta bug Shiv for a fix.

[ttbmer]

Originally Posted by themyst

Look at his sig.

I actually meet him before and his wasn't running aftermarket. I'm also on my iPhone app so signature are not available

[ttbmer]

Originally Posted by Longboarder

Hey what's up David it's Adam. Did you get your car running right?

Check out this log - it's from my race against you at the airstrip event. My meth boiled over in the lines waiting forever on the hot taramac and so my meth didn't flow. Check out the 80c inlet temps. I think I could have ran faster! lol

I know man. Yeah I was runing 15psi the whole time and didn't even know it. Thanx to shiv. I parted out my car. Moving on to GTR

[Ilma]

Originally Posted by themyst

PS: you're flatlining timing. Whatever happened to this being fixed? Every auto Procede log i've seen shows this flatlining behavior.

..........

Ran three just like this one today:

6AT

Running the latest dynamic meth maps.

i can still flatline once in a while, but it sems to be more the exception than the norm.

I don't think Shiv did anything to address the issue.

Doesn't seem to happen on ALL procede 6AT's.

I remember you switching to JB and Cobb and still flatlining on those tuning platforms yourself.

I was watching closely because I would have jumped ship had that problem been solved, but from what I see......it isn't.

[OpenFlash]

+1
The flatlining issue isn't tune-specific, but rather a result of knock control activity. Running more boost without supporting octane/mods will make it happy more often. I suspect exhaust backpressure is the biggest contributor to this issue which is why octane only helps up to a point. If you are running the stock turbos at high boost, it's likely to happen. With 6ats, it's more likely because they boost spike at the upshift instead of dipping between gears as on a 6MT.

Ps... Nice logs Ilma. 16-17psi with full advance is really the sweet spot for a stock turbo car. Trying to support over that makes things less consistent (although still faster).

[Ilma]

Originally Posted by shiv@vishnu

+1
The flatlining issue isn't tune-specific, but rather a result of knock control activity. Running more boost without supporting octane/mods will make it happy more often. I suspect exhaust backpressure is the biggest contributor to this issue which is why octane only helps up to a point. If you are running the stock turbos at high boost, it's likely to happen. With 6ats, it's more likely because they boost spike at the upshift instead of dipping between gears as on a 6MT.

Which is why I turned down the boost by 1 psi being on stock cats.

The engine feels happier there

[OpenFlash]

Originally Posted by Ilma

Which is why I turned down the boost by 1 psi being on stock cats.

The engine feels happier there

Yep, also helping is that you are runnin on 93oct and not the 91 us west coasters live with. Pushed to the octane limit, take makes a difference even when running meth.

[OpenFlash]

@Longboarder, just drop your boost. The more boost you try to run up top, the bigger your upshift boost spike will be. This is because the high rpm/high boost scenario, makes those turbos spin so fast they cannot deccel quick enough as the RPM drops. Lower engine RPM+same turbo RPM= more boost. And if boost is much greater than boost target, you will likely see a timing reduction.

[themyst]

Originally Posted by shiv@vishnu

+1
The flatlining issue isn't tune-specific, but rather a result of knock control activity. Running more boost without supporting octane/mods will make it happy more often. I suspect exhaust backpressure is the biggest contributor to this issue which is why octane only helps up to a point. If you are running the stock turbos at high boost, it's likely to happen. With 6ats, it's more likely because they boost spike at the upshift instead of dipping between gears as on a 6MT.

Ps... Nice logs Ilma. 16-17psi with full advance is really the sweet spot for a stock turbo car. Trying to support over that makes things less consistent (although still faster).

I distinctly remember you claiming my basic meth kit as the problem, and that if I bought a PWM meth kit, that my issue would be resolved. Turns out, it happens on pump gas, it happens on meth, and has nothing to do with the claimed superiority of your meth kit.

If you're up for it, I can link to those threads.

And can you explain why I flatline in the 6000-6400 range, but not below 6000 but not above 6500+ RPM on Cobb? It CAN be tuned out. You just don't know how.

And furthermore, it appears something your tune is doing makes the timing flatline even worse on your tune than on other tunes such as Cobb and JB4. If we could see what specifically your tune does that causes timing flatline to be even worse than on other solutions, it could be a start for all of us to have a fix. And it's troubling because being short 10+ degrees of timing will be a major impact to performance.

PS - It has nothing to do with boost pressure. Ilma flatlined timing on low boost (14 psi). I've flatlined at 16 psi.

Not trying to thread jack, but it's interesting to see a purported tuner do a complete 360.