Hyundai Amica Si - hesitation

I've experienced this on two cars, a Peugeot 406 1800 and a Proton 1500. It manifested as: starting was fine but within the first minute or two of pulling away, when pressing the accelerator, all engine power would disappear for a moment, to return as it nothing had happened. The Proton only ever did it after a cold start but the 406 might do it again a couple of hours later, if driven continuously.

In both (my) cases it was tracked down to a dodgy Manifold Absolute Pressure (MAP) sensor, on or connected to the inlet manifold.

As a reasonably experienced home mechanic, I changed them myself, each in less than 30 minutes. The new 406 MAP sensor cost me under £50 from GSF. The Proton dealer wanted over £100 for a new one so my local scrapyard let me remove one from one of their less-than-lovely cars for £1...

Same as many cars - an incentive to stay close to your friendly Hyundai dealer!