Hyundai i20 feels like it is going to stall when moving off in first gear, shudders

Question

2017 i20 petrol manual.

For the past week it has felt very hesitant when pulling off in first gear. It feels like it will stall ( though it doesn't), shuddering.

2nd gear can have the same issue too if going at very slow speed (less than 10mph)

No engine lights are on. Any ideas what might be the cause?

The issue started right after getting an MOT, not sure if that is coincidence or related

Thanks in advance

Edit : it also seems to be a bit worse when the car is cold, and gets a little better as it warms up.

Adding a bit more gas and just lifting the clutch as normal reduces the shuddering, and it doesn't stall

Answer 1

I would start diagnosing this by investigating whether there was an issue with a single cylinder in the engine. One cylinder not firing correctly can cause shuddering and a lack of power which will be more obvious at lower engine speeds and when the vehicle is moving slowly.

After removing the engine cover, it should be possible to identify the ignition coils for each spark plug. By disconnecting them individually and so disabling that cylinder and running the engine, it would become apparent if one of the cylinders did not make a change to the engines smoothness when disconnected.

Disconnecting a good cylinder would make the engine run worse. Disconnecting a bad cylinder may not be noticeable.

If you are not confident with doing a procedure such as this, you will likely need to get a mechanic to diagnose the issue for you.