Throttle blips during downshift
#1
Throttle blips during downshift
Whenever the trans downshifts during WOT, the throttle will go from 99 to 50ish then back to 99 very quickly. This causes a very annoying delay and stress on belt tensioner from the blower.
Case in point, frame 3950 is a 4->2 downshift, and frame 4230 is a 3->2 downshift. Any help would be appreciated!
Thanks
mods: 2004 lm7 5.3, gt2-3 cam, tvs1900 w/ 3" pulley, performabuilt level 3 4l60e, pi triple disc 2600 stall, tbss 87mm tb with dr.x adapter harness
You need to change the two .txt files to .cfg if you want to see what I see on the on the logs.
Case in point, frame 3950 is a 4->2 downshift, and frame 4230 is a 3->2 downshift. Any help would be appreciated!
Thanks
mods: 2004 lm7 5.3, gt2-3 cam, tvs1900 w/ 3" pulley, performabuilt level 3 4l60e, pi triple disc 2600 stall, tbss 87mm tb with dr.x adapter harness
You need to change the two .txt files to .cfg if you want to see what I see on the on the logs.
#3
TECH Senior Member
iTrader: (7)
I to this day randomly still get that. More so with the 60e but still with the 80e. You don't have to log it to know its happening. I still get small timing pulls at shifts that I can't stop. It has to be in the TQ management/abuse routines but I've yet to find it. Sorry no help and will subscribe to the thread to see if someone chimes in with a fix.
#5
Me and Dr.X have been working on this the last few days through email, and still havent gotten very far. This is my last email response to him after I tried raising the P0106 max map limits to no avail.
Interestingly, I noticed the MAP starts to drop before the throttle starts to close which leads me to believe the throttle is being closed because of the blower, not in spite of it. I need to cut out some things to get a higher frame rate since there is roughly 1 frame difference (1/10th sec) between the map dropping and throttle starting to close.
I looked backed through the logs and this is consistent in all of them although the degree of throttle and map change varies.
Interestingly, I noticed the MAP starts to drop before the throttle starts to close which leads me to believe the throttle is being closed because of the blower, not in spite of it. I need to cut out some things to get a higher frame rate since there is roughly 1 frame difference (1/10th sec) between the map dropping and throttle starting to close.
I looked backed through the logs and this is consistent in all of them although the degree of throttle and map change varies.
Last edited by Atomic; 06-17-2010 at 10:57 PM.
#10
Yea. The torque reduction just changes the spark advance though, not throttle. And the problem happens after it has already shifted.
Look at the top section, the blue line is TPS, white line is MAP, red is RPM, and green is MPH. Notice how both TPS and MAP tank for a second, then recover after its already shifted...
Look at the top section, the blue line is TPS, white line is MAP, red is RPM, and green is MPH. Notice how both TPS and MAP tank for a second, then recover after its already shifted...