Gas/Throttle pedal delay
02-18-2017, 09:52 AM
#1
Gas/Throttle pedal delay
Has anyone experienced a throttle/gas pedal delay when coming to an "almost" complete stop, then trying to get back on throttle?
I have a delay in throttle application.
When I come to a COMPLETE stop I don't have the delay, it's just when I'm maybe going 1-2 MPH and then try to get back on throttle, I can depress the throttle 1/4 way, and for about 1/2 second nothing happens, then it kicks in with a fury.
I realize it's drive by wire, but with this delay it's actually semi dangerous.
Anyone else have this issue, or know a way to improve??
I have a delay in throttle application.
When I come to a COMPLETE stop I don't have the delay, it's just when I'm maybe going 1-2 MPH and then try to get back on throttle, I can depress the throttle 1/4 way, and for about 1/2 second nothing happens, then it kicks in with a fury.
I realize it's drive by wire, but with this delay it's actually semi dangerous.
Anyone else have this issue, or know a way to improve??
02-18-2017, 10:07 AM
#2
What engine? The gasoline has a bit of lag if you catch the tranny right when it is downshifting. The diesel has more lag due to nature of Diesel engine and if you catch the tranny downshifting.
Ether way if you expect m3 individual throttle bodies one of the most responsive engines type of throttle response- you are not getting it by a long shot.
Remember, just like most big and heavy benzes you are not driving it, but rather going for a ride in one
Ether way if you expect m3 individual throttle bodies one of the most responsive engines type of throttle response- you are not getting it by a long shot.
Remember, just like most big and heavy benzes you are not driving it, but rather going for a ride in one
Last edited by alx; 02-18-2017 at 10:11 AM.
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StradaRedlands (02-18-2017)
02-18-2017, 03:39 PM
#3
What engine? The gasoline has a bit of lag if you catch the tranny right when it is downshifting. The diesel has more lag due to nature of Diesel engine and if you catch the tranny downshifting.
Ether way if you expect m3 individual throttle bodies one of the most responsive engines type of throttle response- you are not getting it by a long shot.
Remember, just like most big and heavy benzes you are not driving it, but rather going for a ride in one
Ether way if you expect m3 individual throttle bodies one of the most responsive engines type of throttle response- you are not getting it by a long shot.
Remember, just like most big and heavy benzes you are not driving it, but rather going for a ride in one
02-19-2017, 12:40 PM
#6
driving manual cars is similar. if you are holding 2nd gear when slowing down and at 5-10mph you want to accelerate again, your downshift to 1st is very slow (with careful application of clutch pedal and or matching rpms of the engine or often both) to allow the engine flywheel and clutch plates to sync up so the 2-1 shift is without much jerk.
in the mb implementation while the tranny is doing the tricky (from comfort perspective) 2-1 shift the throttle is delayed/ held so a change in engine rpms doesnt mess up the process.
i hope it makes sense.
if the delay really bugs you it is possible that the 2-1 downshift adaptation has gone super slow. a tcu reset might or might not improve the perceived delay.
Last edited by alx; 02-19-2017 at 12:45 PM.
The following users liked this post:
StradaRedlands (02-20-2017)
02-19-2017, 03:04 PM
#7
it would do it only when you catch it right when it is about to downshift. for some driving styles that is never, for some happens only so often, for others every time. the shifting strategy of 722.9 tranny is such then when slowing down it will hold lower gears longer to reduce jerking when downshifting... thus if during normal driving your truck may shifting to 4rd gear at 35 mph, when slowing down the truck might hold 4th all the way down to 25 mph ... however, if slowing down and at certain speed (say 5-10 mph) if you press the throttle the tranny downshifts (slowly) to improve smoothness and improve engine response for the subsequent acceleration.
driving manual cars is similar. if you are holding 2nd gear when slowing down and at 5-10mph you want to accelerate again, your downshift to 1st is very slow (with careful application of clutch pedal and or matching rpms of the engine or often both) to allow the engine flywheel and clutch plates to sync up so the 2-1 shift is without much jerk.
in the mb implementation while the tranny is doing the tricky (from comfort perspective) 2-1 shift the throttle is delayed/ held so a change in engine rpms doesnt mess up the process.
i hope it makes sense.
if the delay really bugs you it is possible that the 2-1 downshift adaptation has gone super slow. a tcu reset might or might not improve the perceived delay.
driving manual cars is similar. if you are holding 2nd gear when slowing down and at 5-10mph you want to accelerate again, your downshift to 1st is very slow (with careful application of clutch pedal and or matching rpms of the engine or often both) to allow the engine flywheel and clutch plates to sync up so the 2-1 shift is without much jerk.
in the mb implementation while the tranny is doing the tricky (from comfort perspective) 2-1 shift the throttle is delayed/ held so a change in engine rpms doesnt mess up the process.
i hope it makes sense.
if the delay really bugs you it is possible that the 2-1 downshift adaptation has gone super slow. a tcu reset might or might not improve the perceived delay.
I'm assuming the TCU is the computer? Would a sprint booster help at all or is this all from the trans computer?
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02-27-2017, 09:09 PM
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02-28-2017, 06:05 PM
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2007 GL450
It accelerates the throttle input. So pushing the throttle down 1 inch, now the motor thinks you're pushing it down 1-1/2 inches.
I'm getting away from it because I'm going offroad, which calls for more delicate throttle work, and also my spastic daughter is learning how to drive.
I'm getting away from it because I'm going offroad, which calls for more delicate throttle work, and also my spastic daughter is learning how to drive.
Last edited by eric_in_sd; 02-28-2017 at 06:08 PM.
