Help please, no acceleration after shifting into 5th during hard acceleration
07-15-2010, 07:57 AM
#1
Help please, no acceleration after shifting into 5th during hard acceleration
I have noticed this problem when I push my car to redline between 4th and 5th gear. The first time was at the track day at thunder hill, and again last night at sac raceway. When I shift around 6500rpms into 5th gear and and push down on the accelerator pedal, the car is un-responsive, it begins to slow down, the engine does not rev up until I let up on the accelerator pedal and push back down on it. At the track day, I thought that it was possibly due to low fuel (around a ¼ tank) and the fuel was moving beyond the pickup tube. Last night at sac raceway, I had a full tank of fuel. Someone mentioned something about shift knock which I know nothing about. Does anyone know what may be causing this problem or have any recommendations on how to fix it? I had a buddy at the track day at thunder hill that was experiencing the same problem under the same conditions so I know it has happened to others.
My car is 06 TR, VF39, STi TMIC, MBC, 3” Catted DP full exhaust, EL headers, inlet, intake, and pro tuned. It also has the wallbro fuel pump.
Thanks!!
My car is 06 TR, VF39, STi TMIC, MBC, 3” Catted DP full exhaust, EL headers, inlet, intake, and pro tuned. It also has the wallbro fuel pump.
Thanks!!
07-15-2010, 08:52 AM
#2
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Im not great at these things so its only speculation but a few questions. You may be getting your top mount really hot and by the time you get to 5th your car may be pulling alot of timing.
Again im no pro tuner but that would be my best edumacated guess.
Again im no pro tuner but that would be my best edumacated guess.
07-15-2010, 09:02 AM
#4
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I have noticed this problem when I push my car to redline between 4th and 5th gear. The first time was at the track day at thunder hill, and again last night at sac raceway. When I shift around 6500rpms into 5th gear and and push down on the accelerator pedal, the car is un-responsive, it begins to slow down, the engine does not rev up until I let up on the accelerator pedal and push back down on it. At the track day, I thought that it was possibly due to low fuel (around a ¼ tank) and the fuel was moving beyond the pickup tube. Last night at sac raceway, I had a full tank of fuel. Someone mentioned something about shift knock which I know nothing about. Does anyone know what may be causing this problem or have any recommendations on how to fix it? I had a buddy at the track day at thunder hill that was experiencing the same problem under the same conditions so I know it has happened to others.
My car is 06 TR, VF39, STi TMIC, MBC, 3” Catted DP full exhaust, EL headers, inlet, intake, and pro tuned. It also has the wallbro fuel pump.
Thanks!!
My car is 06 TR, VF39, STi TMIC, MBC, 3” Catted DP full exhaust, EL headers, inlet, intake, and pro tuned. It also has the wallbro fuel pump.
Thanks!!
07-15-2010, 09:07 AM
#5
I'll call my tuner today, when you guys say pull timing, is there a parameter in my access port that I could monitor to see if this is happening? Does anyone have an idea of what point the timing would render no power? I appreciate your opinions and input!
07-15-2010, 09:13 AM
#6
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If the car is pulling fine in lower gears it's possible as others have said it's pulling timing in your highest load gear, rather than risk damaging your motor conducting runs to log I would suggest as others have contacting your tuner as he will be able to conduct those tests for you with greater margin of safety.
Mike
07-15-2010, 09:18 AM
#7
If your using an AP 2 you can log pretty much everything you need and spit it out as a .csv to view on a PC.
If the car is pulling fine in lower gears it's possible as others have said it's pulling timing in your highest load gear, rather than risk damaging your motor conducting runs to log I would suggest as others have contacting your tuner as he will be able to conduct those tests for you with greater margin of safety.
Mike
If the car is pulling fine in lower gears it's possible as others have said it's pulling timing in your highest load gear, rather than risk damaging your motor conducting runs to log I would suggest as others have contacting your tuner as he will be able to conduct those tests for you with greater margin of safety.
Mike
Let's hope it was just the hot weather. Hitting up the tracks alot aren't you 
07-15-2010, 07:15 PM
#10
A little, trying to get my time down. Going to get my car looked at, thinking about logging a couple passes next week to figure out what this is. Never happened when I had my FMIC last year. Nothing worse than your car falling on its face when you need the power. Will keep you posted. Did you ever get your wiring fixed up on your STi?
07-15-2010, 09:07 PM
#12
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Hey!
A little, trying to get my time down. Going to get my car looked at, thinking about logging a couple passes next week to figure out what this is. Never happened when I had my FMIC last year. Nothing worse than your car falling on its face when you need the power. Will keep you posted. Did you ever get your wiring fixed up on your STi?
A little, trying to get my time down. Going to get my car looked at, thinking about logging a couple passes next week to figure out what this is. Never happened when I had my FMIC last year. Nothing worse than your car falling on its face when you need the power. Will keep you posted. Did you ever get your wiring fixed up on your STi?
07-15-2010, 10:01 PM
#13
I would like to when the heat passes, i have new sways that didn't show up in time for the last track day. I have a list of many different track days, if I get this problem with car fixed, I will totally be down for more track time, it's a lot of fun!! You going to run yours sometime?
07-16-2010, 07:43 AM
#15
No CEL, totally bizarre, it drives completely fine under normal conditions too. Did yours happen at the end of 4th going into 5th at WOT?
Hey Matt, No real word yet, going to try to get in when EQ gets some time, they are pretty swamped right now. I might go back next week and data log a couple passes and try to get it to do it again, shouldn't be to hard, it did it 5 out of the 8 passes I made.
I will post what ever I find. Starting to really wonder if it is timing, never happened before when I had my FMIC, just wouldn't expect it to retard the timing so far that the motor would basically make no power.
Hey Matt, No real word yet, going to try to get in when EQ gets some time, they are pretty swamped right now. I might go back next week and data log a couple passes and try to get it to do it again, shouldn't be to hard, it did it 5 out of the 8 passes I made.
I will post what ever I find. Starting to really wonder if it is timing, never happened before when I had my FMIC, just wouldn't expect it to retard the timing so far that the motor would basically make no power.