Data logged w/TunerPro -Flooring from a dead stop causes severe hesitation or misfire
06-29-2014, 06:44 PM
#1
Data logged w/TunerPro -Flooring from a dead stop causes severe hesitation or misfire I've been chasing this issue for a few years now
-Currently rocking a brand new 1500 mile Delphi. It's not the opti, trust me, lol
-Original ICM I'm pretty sure.
-MSD Ignition Coil
-Plugs are NGK, and are about a year old
-Over the valve cover MSD 8.5mm wires
-02's were put on about three years ago
-LT4 Knock Module.
I floor it from a dead stop, and the car basically sits there and dies... Finally catches, and then misfires through out the RPM range.
No issues that I can tell from flooring it while moving.
Tune file #1 (Casually driving around town, with very severe flooring problem at very end)
Tune file #2 (Not as severe this time, but still there, straight to the misfire problem)
Files are in a zip file, and are named appropriately
-Currently rocking a brand new 1500 mile Delphi. It's not the opti, trust me, lol
-Original ICM I'm pretty sure.
-MSD Ignition Coil
-Plugs are NGK, and are about a year old
-Over the valve cover MSD 8.5mm wires
-02's were put on about three years ago
-LT4 Knock Module.
I floor it from a dead stop, and the car basically sits there and dies... Finally catches, and then misfires through out the RPM range.
No issues that I can tell from flooring it while moving.
Tune file #1 (Casually driving around town, with very severe flooring problem at very end)
Tune file #2 (Not as severe this time, but still there, straight to the misfire problem)
Files are in a zip file, and are named appropriately
06-29-2014, 08:50 PM
#2
TECH Addict
Your Casual driving log file, I couldn't get it to not jump around. It's like it's got a bad connection to the PCM. I tried reloading and restarting my Tuner Pro to no avail.
The full throttle run shows you're running lean. Then you floor it and it goes to 128 on your BLMs. Do you have the BLM locker on for WOT? IIRC, if you are running lean when you enter WOT, GM had it continue to add fuel per the BLM trims. But your still going from adding fuel to not. Do you have a locker?
You have much better air than I do (100+kPa vs my 93-94kPa).
Do you have a copy of your tune to post up?
Your issue seems to start when you last replaced the O2's according to your first post, have you tried replacing those again?
The full throttle run shows you're running lean. Then you floor it and it goes to 128 on your BLMs. Do you have the BLM locker on for WOT? IIRC, if you are running lean when you enter WOT, GM had it continue to add fuel per the BLM trims. But your still going from adding fuel to not. Do you have a locker?
You have much better air than I do (100+kPa vs my 93-94kPa).
Do you have a copy of your tune to post up?
Your issue seems to start when you last replaced the O2's according to your first post, have you tried replacing those again?
06-30-2014, 06:45 AM
#3
Your Casual driving log file, I couldn't get it to not jump around. It's like it's got a bad connection to the PCM. I tried reloading and restarting my Tuner Pro to no avail.
The full throttle run shows you're running lean. Then you floor it and it goes to 128 on your BLMs. Do you have the BLM locker on for WOT? IIRC, if you are running lean when you enter WOT, GM had it continue to add fuel per the BLM trims. But your still going from adding fuel to not. Do you have a locker?
You have much better air than I do (100+kPa vs my 93-94kPa).
Do you have a copy of your tune to post up?
Your issue seems to start when you last replaced the O2's according to your first post, have you tried replacing those again?
The full throttle run shows you're running lean. Then you floor it and it goes to 128 on your BLMs. Do you have the BLM locker on for WOT? IIRC, if you are running lean when you enter WOT, GM had it continue to add fuel per the BLM trims. But your still going from adding fuel to not. Do you have a locker?
You have much better air than I do (100+kPa vs my 93-94kPa).
Do you have a copy of your tune to post up?
Your issue seems to start when you last replaced the O2's according to your first post, have you tried replacing those again?
I'll try and record another casual driving file today.
My car is on a stock tune, the O2's were replaced when I had headers put on my car. I was under the impression that the PCM ignored O2 information under WOT. Locally they're $100 or so each, would like to avoid replacing them if they're okay. I think I may be wrong on when I replaced them, could've been three years ago.
My car should have whatever the defaults are when it comes to everything.
So why would it be running lean? Something fuel related? I replaced the fuel pump about two years ago.
06-30-2014, 03:10 PM
#4
TECH Addict
If you're stock with a stock tune and your issues started with O2's I'd get those replaced.
I was mistaken though, it wasn't running lean. It was rich.
The Stock tune will ignore the BLM's only if the engine was reading rich or good. If it was lean it'll keep what ever trims it had before WOT.
I was mistaken though, it wasn't running lean. It was rich.
The Stock tune will ignore the BLM's only if the engine was reading rich or good. If it was lean it'll keep what ever trims it had before WOT.
