Vw polo shuddering/failing to accelerate or change gears at certain times

Question regarding the car failing to accelerate properly that only happens just when I start driving it.

Turn on the car and go, it accelerates fine in first gear. When I switch to second gear it starts shuddering at 20mph and won’t go any faster no matter how hard I push the pedal. I switchh to 3rd and its fine until I get to 30mph and then the same thing. I pull over, turn off the car, restart and it’s all fine.

I drive a 2004 volkswagen polo 1.2L engine with 100,000 miles or 160k kilometres.

"I pull over, turn off the car, restart and it’s all fine. "

Have you tried pulling over and just letting it idle for a few minutes? I’m thinking a failing temp sensor.

No, haven’t tried that. So I should pull in and let it sit there, still on, in 1st gear?

I’d just put it in neutral.

Sounds as if you are in limp mode. http://www.myturbodiesel.com/wiki/limp-mode-fix-repair-troubleshooting-vw-seat-skoda-audi-tdi-engine/