Engine bucking at low rpm

[SiR R8TD]

This is one of the most annoying things about my EP. When I'm creeping in traffic or getting off/on the throttle quickly, the motor "bucks", especially at lower rpm's. It feels as if it's rocking back & forth violently. I checked out the motor mounts & their fine. I'm swapped w/ a Z1, KPRO, Quaife LSD & Exedy stg2 clutch. Any ideas?

[bmyers4321]

how low rpm are we talking here. i never had a problem with this bucking(or jerking i guess you cou say) unless i let it get way to low.

[SiR R8TD]

how low rpm are we talking here. i never had a problem with this bucking(or jerking i guess you cou say) unless i let it get way to low.

Around 1000 - 2500rpm when I'm creaping in traffic and when I get on/off the throttle at any rpm around 1000-4000rpm. Also when it's at high idle when she's warming up.

[Kerby]

its your vtak kicking in.:painkiller:

who installed the clutch? maybe the clutch wasn't installed correctly.

[cow]

You have too much torque.

(sorry, worthless reply. bump.)

[4angrybadgers]

Do you have Kpro? My tune has some low-RPM bucking issues. I've looked all over the Hondata forums, and there seem to be several issues that can cause it. When I get back to my personal computer at home I can look for the relevant threads.

[SiR R8TD]

Do you have Kpro? My tune has some low-RPM bucking issues. I've looked all over the Hondata forums, and there seem to be several issues that can cause it. When I get back to my personal computer at home I can look for the relevant threads.

Thanks, I appreciate it.

[bigo711]

Around 1000 - 2500rpm when I'm creaping in traffic and when I get on/off the throttle at any rpm around 1000-4000rpm. Also when it's at high idle when she's warming up.


I think low RPM is normal b/c my car does the same thing when it's brand new..
it jerks in 1st gear low rpm... around 1000..

there has been discussion about this about 3 years ago. I think the conclusion was that our motor lacks torque, which caused the jerking action. I don't know the reasoning behind the conclusion tho@@

[4angrybadgers]

Thanks, I appreciate it.

No problem. :mcool: Here are the two I had found a few months ago:
http://www.hondata.net/forum/viewtopic.php?t=7038
http://www.hondata.net/forum/viewtopic.php?t=6848

Like I said, my car bucks worse than it did before the JRSC/tune. I've been meaning to play around with Kpro and fix it, but I never have the time.

[v1c10us]

everyones car does this, its just the way you drive.
If i put her in first and slow down, once i start going slow enough it bucks.
then if you touch the gas it bucks much harder. The only way I've gotten around it is to rev to about 1500-2000 and just slip the clutch out.
Or just slip the clutch out without revving..
you cant really just, gas it and let off and slow down and gas it without the car bucking

[4angrybadgers]

everyones car does this, its just the way you drive.
If i put her in first and slow down, once i start going slow enough it bucks.
then if you touch the gas it bucks much harder. The only way I've gotten around it is to rev to about 1500-2000 and just slip the clutch out.
Or just slip the clutch out without revving..
you cant really just, gas it and let off and slow down and gas it without the car bucking

You're right, every car will buck a bit near idle. But there are certain things in a tune that can make it buck harder than normal and over a wider RPM range, and it may be possible to smooth it out with street tuning. For example, mine will buck in 2nd and 3rd (maybe even 4th, I don't remember) if I try to keep it around 2k RPMs with very light throttle - it never did that prior to Kpro.

[SiR R8TD]

You're right, every car will buck a bit near idle. But there are certain things in a tune that can make it buck harder than normal and over a wider RPM range, and it may be possible to smooth it out with street tuning. For example, mine will buck in 2nd and 3rd (maybe even 4th, I don't remember) if I try to keep it around 2k RPMs with very light throttle - it never did that prior to Kpro.

That's what I've noticed. I try not to bog the motor down, but in stop & go traffic I have no choice. I'm scheduled for a dyno session next week. I'll definately let him know about the "bucking" issue. I'll post up my datalog tomorrow & see what you guys think.