Hey dude I'm in Goose Creek. If you need any help or a second set of eyes to help feel free to hit me up! I had the red Gen 1 Speed 3 with the STI wheels until I sold it a few months ago.
Stuttering/Hesitation after many, many changes.
- Thread starter Adrian Hayden
- Start date
I was able to fix the problem yesterday.
Here is what tipped me off: (red - load, blue - APP, purple - RTP)
All over my logs, relative throttle spikes and dips erratically. While the ECU can get involved and cut throttle back if need be, there is no scenario where 25% APP should result in the throttle body spiking open to over double that (~55%). My friend brought his speed3 over, and we swapped his throttle body in. The problem went away completely. Looking at all of my logs, the spikes in relative throttle started on the first log with the stumble. They were nonexistent on my logs with his throttle body.
Here is what tipped me off: (red - load, blue - APP, purple - RTP)
All over my logs, relative throttle spikes and dips erratically. While the ECU can get involved and cut throttle back if need be, there is no scenario where 25% APP should result in the throttle body spiking open to over double that (~55%). My friend brought his speed3 over, and we swapped his throttle body in. The problem went away completely. Looking at all of my logs, the spikes in relative throttle started on the first log with the stumble. They were nonexistent on my logs with his throttle body.
What I felt was the throttle body pseudo-randomly deciding to wildly choke/restore airflow.
Agreed. It was my last idea/theory before being truly stumped. Even did a compression test because I was worried about the injector seals.
I think it was a failing sensor and overcorrecting, or something similar. Probably didn't throw the CEL because it was still talking back to the computer. Just glad it was something "simple".