Stew

iTrader: (11)

Just so we cancel that out, the logs were taken around 7:45 PM last night in CT, not sure of the actual temp but it was cooling down nicely at that point.

mchuang

iTrader: (11)

If I were you to be on the safe side I would just go head and drop some timing on the map and richen it up and then work your way back up cause right now your starting in the danger zone, I wouldnt be making WOT pulls with that kind of knock. Is it tuned by a tuner or some map you threw together?

Stew

iTrader: (11)

This map was professionally tuned. The only things I've touched are:

- lowered the stationary rev limiter
- scaled up the injectors from 513 to 600(ish). (injectors are 720cc)

There have been no mods added since the tune. Tune was performed about 2 months ago, and the car was running great until last week.

MalibuJack

iTrader: (5)

Did you adjust the maps after you rescaled the injectors?

RazorLab

iTrader: (8)

Wait, you scaled the injectors after the tune? No wonder. You have to tune AFTER the injectors are scaled. All your fueling is scaled over now. You are probably running insanely lean. Stop driving the car.

AlwaysinBoost

iTrader: (17)

that would make perfect sense why his target A/F was so high... kind of a crappy way to tune IMO.

Mad_SB

iTrader: (8)

yeah man, put the scale back to 513..... that one change shifted your whole map lean, I'm supprised it was not knocking sooner in the rev range.


So, I gotta ask man, why did you change the injector scaling in the first place?

MalibuJack

iTrader: (5)

It was based on another suggestion in another thread.. Only it was assumed the tune would have been adjusted accordingly afterwards..

chmodlf

iTrader: (19)

No wonder you guys were haulin' a at the autox. Lean makes a mean machine.

Stew

iTrader: (11)

The idea was to bump up the scaling a bit on the injectors as an attempt to fix a WOT -> 0 throttle stall. The scaling was done yesterday a hour before the logs were run. We'll scale back down the injectors and run a detailed log tonight. However, the scaling did fix that problem.

The car has been experiencing the same stumbling issues for the past few weeks, independant of the injector scaling (which could possibly be adding to it, but the car acts the same overall).

RazorLab

iTrader: (8)

Yup, since your injectors weren't scaled correctly you will get that decel stall. If you scale them correctly and tune for it you will be much happier.

I scaled a 03 evo running 720's this last weekend. Runs like a top.

Mad_SB

iTrader: (8)

Ahhh,

Hmm, is it a missfire stuble or a unmetered air stumble?
Did the throttle off stall start at the same time?
What about the boost creep, did it start at the same time?
Was any work done on the car (no matter how trivial) at the time this started?

I would not think it to be tune related, but rather part failure, if it ran fine a couple weeks ago on the same tune, something else has changed and most likely something has broken or worn out.

Obvious things that come to mind are vacume leak, fuel pump, and wiring. Maybee a perforation in your boost controller plumbing? A bad ground connection? Plug fouling?

Stew

iTrader: (11)

-Seems more like a unmetered air stumble than a missfire.
-Throttle off started before these issues, mainly at the point of the tune.
-Boost creep started well after the tune/throttle off, about the same point as the stumble.
- no work at all was done to the car

Part failure is very likely.

I would think with a vacuum leak we would not be getting the 23.8 psi.

We made some changes tonight and recorded a better log. I'm working on now and I'll post it in a bit, or in the AM.

jrave

this is actually my car that Stew and I have been screwing around with.

for mad_VIII, i did actually have to replace the TPS shortly after the tune (old TPS was sticking). the car was fine until only the last 2 weeks.

and i have trouble saying TPS without thinking of Office Space...

Stew

iTrader: (11)

Alrighty.. The changes we made tonight were:

- Injectors scaled back to 513
- Wastegate % turned down, boost peaks at 20.9 psi in 3rd, and around 21.3 psi in 4th.

Here are the attatched logs. Both runs were from around 3000 RPM, to 7000 RPM. Car definitely had the same stumbling as before. I loaded up the new data.xml file so we have octane number now. Also had a better laptop, so we could get 90 readings/second as opposed to 23. All values were logged.

Also to be noted, the car is throwing 3 codes that come right back as quick as you can clear them. Well, the knock sensor and vehicle speed sensor don't come back until you get moving, but the barometric pressure sensor comes back immediately.

Codes:
- Vehicle speed sensor
- Barometric pressure sensor
- Knock sensor

Logs attached.