First drive with turbo and ms. Sputters and backfires at 4k
#1
First drive with turbo and ms. Sputters and backfires at 4k
Went for my first drive on brains base maps and above 4k rpm it sputters and backfires and won't accelerate any above 4000 rpm. Rev limit is 7100. Overboost set to 10psi. Will add video shortly. Also I noticed the center led is lit up on my ms now and it never used to.
edit: wont let me upload iphone video but what do i need to log/take screenshot of to be of any benefit to yall?
edit: wont let me upload iphone video but what do i need to log/take screenshot of to be of any benefit to yall?
Last edited by rigidbigelsworth; 10-06-2011 at 07:20 PM.
#3
Like Brain says, datalog and see what's going on that's going to tell you more than any video or picture ever could.
As for the problem, my guesses...
1. Overboost is coming on. Do you have a boost gauge? What is it showing? If it's near 10psi, that's likely your problem
2. Air/Fuel Ratio is overly rich or lean. What is your wideband reading at idle? Under acceleration? Have you adjusted the fuel map at all?
3. Spark Blowout. What are your spark plugs gapped at? Did you go 1 range cooler on the plugs? If the first 2 have been fixed, pull the plugs and decrease the gap.
I've had similar problems to what you describe under all 3 circumstances. When I loaded the basemap on both my cars it was WAYYY off. Unless you're just plain lucky, you've got a good deal of tuning ahead of you.
As for the problem, my guesses...
1. Overboost is coming on. Do you have a boost gauge? What is it showing? If it's near 10psi, that's likely your problem
2. Air/Fuel Ratio is overly rich or lean. What is your wideband reading at idle? Under acceleration? Have you adjusted the fuel map at all?
3. Spark Blowout. What are your spark plugs gapped at? Did you go 1 range cooler on the plugs? If the first 2 have been fixed, pull the plugs and decrease the gap.
I've had similar problems to what you describe under all 3 circumstances. When I loaded the basemap on both my cars it was WAYYY off. Unless you're just plain lucky, you've got a good deal of tuning ahead of you.
#4
I'll have to get a log up tomorrow
As far as your questions pdexta
1: max psi is around 7 as I have my wastegate set, gauge confirms it
2: idle is around 11 for the most part under hard acceleration it's around 13.5
3: still have stock plugs. What kind of gap should I be aiming for? And what does ' one plug cooler' mean?
Thanks for the quick response
As far as your questions pdexta
1: max psi is around 7 as I have my wastegate set, gauge confirms it
2: idle is around 11 for the most part under hard acceleration it's around 13.5
3: still have stock plugs. What kind of gap should I be aiming for? And what does ' one plug cooler' mean?
Thanks for the quick response
#7
You are either
1. Detonating due to a lean condition. You seriously need more fuel under load. Idle should be 15:1 - 14.5:1 and under boost you should be 12:1-11.5:1 at those boost levels. You adjust these by raising and lowering the values in the VE table NOT the target AFR table (seen this a few times)
or
2. You have spark blowout due to incorrectly gapped plugs. Try lowering your gap to .022-.025 IN ADDITION TO adding more fuel.
Cooler plugs refers to how much heat the spark plug dissipates into the head. Hotter plugs dissipate less than cooler plugs. Hotter plugs tend to run cleaner (not foul as often) but as they are a source of heat in the combustion chamber, then can cause detonation in an already lean mixture or under high load/pressure. I can't remember the plug numbers right now since I haven't bought any in a while, but perhaps someone else can chime in with that.
Good rule of thumb is 1 step colder plug for every additional 100whp btw.
#10
Can y'all tell from looking at my fuel map if I'm starving for gas in boost? They are just a bunch of numbers to me haha
I'll have to start tuning my fuel map tomorrow. Whats a reasonable step size to adjust my fuel values by? 1?5?10?
Thanks for the suggestions
I'll have to start tuning my fuel map tomorrow. Whats a reasonable step size to adjust my fuel values by? 1?5?10?
Thanks for the suggestions
Last edited by rigidbigelsworth; 10-07-2011 at 12:57 AM.
#11
I'll have to get a log up tomorrow
As far as your questions pdexta
1: max psi is around 7 as I have my wastegate set, gauge confirms it
2: idle is around 11 for the most part under hard acceleration it's around 13.5
3: still have stock plugs. What kind of gap should I be aiming for? And what does ' one plug cooler' mean?
Thanks for the quick response
As far as your questions pdexta
1: max psi is around 7 as I have my wastegate set, gauge confirms it
2: idle is around 11 for the most part under hard acceleration it's around 13.5
3: still have stock plugs. What kind of gap should I be aiming for? And what does ' one plug cooler' mean?
Thanks for the quick response
#17
im kinda hesitant to log while purposely hitting a spot that is potentially detonation...
also when looking at my table vs a table brain posted, i have more fuel at high rpm/high boost, and less at low rpm/low boost already...
as far as i know brain is on similar fueling system, stock fuel pump, 460's
am i missing something?
my map is on the left, one brain posted in another thread is on the right
also when looking at my table vs a table brain posted, i have more fuel at high rpm/high boost, and less at low rpm/low boost already...
as far as i know brain is on similar fueling system, stock fuel pump, 460's
am i missing something?
my map is on the left, one brain posted in another thread is on the right
#19
im kinda hesitant to log while purposely hitting a spot that is potentially detonation...
also when looking at my table vs a table brain posted, i have more fuel at high rpm/high boost, and less at low rpm/low boost already...
as far as i know brain is on similar fueling system, stock fuel pump, 460's
am i missing something?
my map is on the left, one brain posted in another thread is on the right
also when looking at my table vs a table brain posted, i have more fuel at high rpm/high boost, and less at low rpm/low boost already...
as far as i know brain is on similar fueling system, stock fuel pump, 460's
am i missing something?
my map is on the left, one brain posted in another thread is on the right