One hit is great, the next is weak, and then it stops entirely. This on-again, off-again behavior usually points to a connection or airflow issue.

1. Clean the contacts: Where the cartridge meets the battery, there are metal contacts. Wipe them gently with a dry cloth or cotton swab to remove any e-liquid residue.
2. Adjust your pull: Pulling too hard can flood the coil with e-liquid, making it gurgle and sputter. Take slower, steadier draws.
3. Rest it if it's hot: If the device feels warm, it might be overheating. Let it sit for 10 minutes before trying again. This can also prevent burnt hits.

Inconsistency can also happen when the e-liquid level is low. If you can see the liquid and it's almost gone, the wick might not be saturated enough to produce consistent vapor.