HELP!!! Bucking Part Throttle
#1
HELP!!! Bucking Part Throttle
I hope this is in the right section. I am experiencing some pretty violent bucking with my evo, seems to only be at part throttle. The problem surfaces within about an hour and a half of interstate driving and to me has no rhyme or reason to when it does it, but it is bucking some at part throttle situations. The only facts I know of are that the car has not thrown any CEL and is registering a really lean AFR when it starts bucking. Like the car is just cutting injectors for whatever reason. It was so bad at one point that the car would not gain speed at all, because all attempts to give throttle would just buck harder.
The car was put on SD about a month ago, stock turbo, stock internals. It made great power and had no issues until recently. Im not too sure if it coincides with the colder weather or if there is a developing problem with something else. I replaced the Walbro 255 with a Deatsch Werks 301 today and seemed to help a bit with this problem (not quite as frequent), but the problem is still present.
Does anyone have any ideas on what could be plaguing me?
The car has all basic bolt ons, FIC 900CC injectors, DW 301 Fuel pump, stock computer with Tephra v5 SD tune on 93 octane.
Thanks for any input!!
The car was put on SD about a month ago, stock turbo, stock internals. It made great power and had no issues until recently. Im not too sure if it coincides with the colder weather or if there is a developing problem with something else. I replaced the Walbro 255 with a Deatsch Werks 301 today and seemed to help a bit with this problem (not quite as frequent), but the problem is still present.
Does anyone have any ideas on what could be plaguing me?
The car has all basic bolt ons, FIC 900CC injectors, DW 301 Fuel pump, stock computer with Tephra v5 SD tune on 93 octane.
Thanks for any input!!
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You may get someone to help you on here. The problem that there are some special requisites for starting a thread on this sub-forum I think. So, the mods may move it over to another section.
#7
Thats it! It seems to be so random that I dont think the tune is at fault, but the car performed just fine on the maf just before the SD tune.
I havent noticed it at all except on the interstate cruising in 5th. Goes WOT just fine, just at times will decide to start bucking part throttle.
I havent noticed it at all except on the interstate cruising in 5th. Goes WOT just fine, just at times will decide to start bucking part throttle.
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#9
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What size injectors? Mine does it in 1st an 2nd say going through a parking lot at low speed I'm also on sd I've heard cop greatly helps this problem but I have no exaperiance with it
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Cold temps outside gradually gets more vilolent if I don't adjust normally shift or push the clutch in I'm heading back up to English racing soon I've heard that this is a pretty commen thing with bigger injectors and sd and posibly big cams i have s2s but like i said mine only happens in low gears at parking lot speeds
like I said some say cop help with it but im sure a good tuner can tune it out I watched tom from tscompusa he has a video of just smooth driving so I'm just guessing it can be tuned to be a little less aggressive
like I said some say cop help with it but im sure a good tuner can tune it out I watched tom from tscompusa he has a video of just smooth driving so I'm just guessing it can be tuned to be a little less aggressive