Hey guys, I have a 2011 tC with an auto. All stock. I've been having a problem lately where the car will suddenly and briefly shudder. To me it feels like the throttle body suddenly shuts, then opens again. Or maybe like a connection is disconnected and reconnected very quickly. The hesitation only lasts for 1\2 a second maybe.
Happens only under slight acceleration, seems like there is a certain spot in the pedal the causes it.
Anyone have any ideas? Can I replace a throttle position sensor, or do I need the whole accelerator pedal assembly? Any connections I should check for tightness?

Edit- See update
Thanks.

 

Ever cleaned your throttle body? To clean the throttle plate, you have to slowly open it. Opening the throttle plate turns plastic gears inside the throttle mechanism. Moving the throttle plate less than carefully might break a gear tooth. This might simulate what you're describing. I don't know whether you can open the gear housing.

 

I have not ever cleaned it.

 

Never encountered a bad throttle position sensor. Wouldn't hurt to unplug it and clean the connector contacts with contact cleaner. Let dry and plug back together.

Visually inspect any plastic connectors for cracks. It's also a good idea to inspect the vacuum hoses for cracks. Sometimes you can cut off the cracked end reuse the same hose.

I'd also consider cleaning the throttle body and the MAF sensor. Walmart has throttle body cleaner and MAF sensor cleaner together in the same kit for ~$5.00. If your throttle body is really dirty, you may need the big can of throttle body cleaner. The little can of MAF sensor cleaner is likely all you'll ever need.

 

vacuum leak

 

Update. I appear to of fixed the issue. I replaced the accelerator pedal assembly with a lower mileage used part.. No more shudder. I suspect that the sensor inside the old pedal was worn out in one small spot, and was causing the ECM to momentarily close the throttle.

 

Good job on your diagnosis, and thanks for the follow-up. .