hesitation after shifting and flooring it
2/22/17, 04:09 PM
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hesitation after shifting and flooring it
I just upgraded (bigger and bolder) everything along the air flow path from air filter to the Supercharger inlet, installed big ID 1000 injectors and got a new tune. Now my 2012 GT is sputtering and stalling for about 2 seconds (it feels like it loses power) after I shift gears and give it gas, especially 3rd to 4th gear
Just before doing all the air flow upgrades and tuning, I gave my Roush a new transmission (Tremec Magnum XL ), and I think the installer did the crank relearn, not sure
I've posted in other forums and got some ideas that I am going implement between tonight and Friday, but wanted to check with you guys too, since I've got about 10 causes for this issue (I got a P0300 - random cylinder misfire last night after starting the car) that I need to narrow down to 1
I've noticed cat temps go over 1,600 degrees, which is high, when I give it gas long enough. These temp levels have never happened before
Tuner says he does not see anything in the tune that would cause the hesitation, but is willing to take another look at the car (the shop is about 200 miles from my house, that is the problem there)
Important: I do not think he did a crank relearn after entering the new gear ratios in the new tune and loading into the PCM - I am trying to establish a cause-effect relationship between new transmission, no crank relearn and new tune with the hesitation at WOT
STFR and LTFR are within normal ranges (-0.7 and 6.2) at idle, but I will run some more tests tonight while driving
I've been very suspicious of a potential vacuum leak somewhere in the air flow path, especially between the new ported SC inlet and the new elbow, but I've smoked it from inside the CAI tube and nothing appears to be sneaking out. Also with those fuel trim numbers, I guess leaks are out of the question (?)
Any ideas and suggestions? I take all of the them and test them asap
Just before doing all the air flow upgrades and tuning, I gave my Roush a new transmission (Tremec Magnum XL ), and I think the installer did the crank relearn, not sure
I've posted in other forums and got some ideas that I am going implement between tonight and Friday, but wanted to check with you guys too, since I've got about 10 causes for this issue (I got a P0300 - random cylinder misfire last night after starting the car) that I need to narrow down to 1
I've noticed cat temps go over 1,600 degrees, which is high, when I give it gas long enough. These temp levels have never happened before
Tuner says he does not see anything in the tune that would cause the hesitation, but is willing to take another look at the car (the shop is about 200 miles from my house, that is the problem there)
Important: I do not think he did a crank relearn after entering the new gear ratios in the new tune and loading into the PCM - I am trying to establish a cause-effect relationship between new transmission, no crank relearn and new tune with the hesitation at WOT
STFR and LTFR are within normal ranges (-0.7 and 6.2) at idle, but I will run some more tests tonight while driving
I've been very suspicious of a potential vacuum leak somewhere in the air flow path, especially between the new ported SC inlet and the new elbow, but I've smoked it from inside the CAI tube and nothing appears to be sneaking out. Also with those fuel trim numbers, I guess leaks are out of the question (?)
Any ideas and suggestions? I take all of the them and test them asap
2/22/17, 06:45 PM
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This smells like a tune issues (something unaccounted for). I doubt the trans has too much to do with it, since all it really changes is gear ratios.
Can you datalog while the issue is happening? Would be interesting to see fuel ratio, spark advance, RPM, fuel pressure and throttle position while the lug is happening.
Can you datalog while the issue is happening? Would be interesting to see fuel ratio, spark advance, RPM, fuel pressure and throttle position while the lug is happening.