Hello every one i have a (opel/vauxhaull) Corsa B 1999 model , the probleme i had lately is that sometimes i lose throttle while pushing the acceleration pedal , and it restores again after a while ( 2 - 3 secs ) and push the car , this happens randomly , but in the past 2 days it happened like twice a minute which is a lot , so what are the things that can cause that ??
Does this engine have an electronic throttle body, or does it use a throttle cable?
I assume you have a manual transmission?
Is the Service Soon/Check Engine light on?
Tester
no it isn’t
throttle cable , and yes it is manual transmission , sorry for not mentioning that 
Then I would check if the engine uses a Manifold Absolute Pressure (MAP) sensor.
The MAP sensor measures the difference between atmospheric pressure and manifold pressure.
From this information, the computer can make adjustments to fuel control and spark advance depending on power demand.
The MAP sensor basically replaced the accelerator pump when engines had carburetors, and the vacuum advance when engines had distributors.
Tester
no the engine doesn’t have the MAP sensor , there is MAF sensor instead