Got that herky jerky feeling

[OldManSTI]

Recently my STi when I?m trying to do a slower, controlled acceleration (like in a construction zone) has been doing a whiplash inducing front to back dance at low rpms (say between 1.5k and 2.5k). I can?t tell if it?s some type of hesitation due to fuel issues, or a drivetrain issue. It smooths out if I push harder on the throttle, but I can tell something?s wrong. I?ve also noticed the 3.2k hesitation is slightly more pronounced, which makes me suspect fuel, but could it be a slipping clutch or a bad engine mount (just spitballing here)?

I also know my power steering pump is about to crap out on me, but I don?t think the two issues are related.

Any help y?all can provide is greatly appreciated.

 

[Alin]

Is this the GR fuel stumble? Odd that it started just recently!

Sent from my E6810 using Tapatalk

 

[HolyCrapItsFast]

I would recommend checking for leaks. Have a smoke test done. 9 out of 10 it is usually a leak.

Do you have a means to log or look at fuel trims? Check them to see if they are high.

Sent from my SM-G892U using Tapatalk

 

[OldManSTI]

I do have an Accessport, so I can pull a log. It?s just been a while since I?ve done so, so can you remind me of the steps?

 

[HolyCrapItsFast]

I don't remember myself LOL.

V2 or V3 access port?

 

[OldManSTI]

I don't remember myself LOL.

V2 or V3 access port?

Ive got a V3.

 

[HolyCrapItsFast]

I just don't remember... I never log with the accessport anymore.

There are a bunch of How To videos on youtube

 

[geekbstrd]

oldmansti, Did you find the problem? I had just purchased my STI 8/2018 and had the GR Stumble, I moved the FRP / fuel pressure regulator manifold reference vacuum hose from the intake track cyl 4 to the bypass valve hose. Fixed about 75% of my problem.