[randyc]

I've been having this slight hesitation/jerk/wave like feeling when i accelerate hard and the RPM goes up above 3500-4000rpm

It feels pretty subtle, like if i relax my head, it goes back and forth. I plugged in my laptop and ran ISTA and left it on while i made a few hard runs around town and the misfiring counter did not clock in any misfire.

FYI spark plugs are new. just replaced them last week.

Could it be the ignition coils if there is no misfire registered in the ISTA/D ? Any ideas

[E81]

In my experience, small misfires don't always throw a code and that can be frustrating. Did this start after you changed the plugs? In that case I would say one of the new plugs is bad.

[F30RiK]

Gap your spark plug at .20.

Had the same problems with my new Oem spark plug, guy at the parts department told me they were already gapped.

EDIT : Still have my problem even with spark plug gapped at .20 (with jb stage 1 on, without it, it's fine)

[okarch]

I had similar experience with new spark plugs which were replaced in a dealer as warranty job. One of them was bad and cracked within several days and put my car in limp mode. Replacement of the bad spark plug resolved the issue.

[randyc]

The jerking happened even before i changed the plugs. in fact that was one of the reasons why i changed my plugs. Good to know that small misfires don't throw a code. I was hesitating to change my ignition coils because no code was thrown and i don't want to spend on the cols unnecessarily. i have clocked 85,000 KM on the car and have not replaced the coils yet. is it about time to do so already ?

Hopefully its not a bad injector or fuel pump

[E81]

Originally Posted by randyc

i have clocked 85,000 KM on the car and have not replaced the coils yet. is it about time to do so already ?

There is no specific replacement interval for the coils. You replace them once they fail. Some fail sooner, some fail later.

[Travelfreek]

Originally Posted by randyc

The jerking happened even before i changed the plugs. in fact that was one of the reasons why i changed my plugs. Good to know that small misfires don't throw a code. I was hesitating to change my ignition coils because no code was thrown and i don't want to spend on the cols unnecessarily. i have clocked 85,000 KM on the car and have not replaced the coils yet. is it about time to do so already ?

Hopefully its not a bad injector or fuel pump

I have had the same issue for a few months on and off now and had replaced plugs just like you and it dont solve it. However today I found a new issue related only to the mechanical waste-gate turbo engines in the 2012 and 2013. I have a vacuum pump that is leaking oil and filling up my turbo waste-gate line with oil (see picture).

I am wondering is the oil is resulting in a lagged response to release or close the wast-gate .

I have it scheduled to be replaced in a few weeks and I will let you know what the effect is.

[mineral_f30]

Any update?