Ever since I bought my Panda, there was this problem: my car pulls equally good when I press acc. pedal more then about 30%. In other words, pressing it to the metal will do the same effect as pressing it up to 30%.
Flying is not my sport. Not even fast driving (my average speed is 40-50 km/h) I just want to climb up my hill (where I live, by the way) without putting into 1st gear half of the way up.
And yes, when the car is cold, he goes better with fulll throtle.
The car is warmer - this problem is worse! maybe this will ring the bell...
That is bugging me because I KNOW it can go better!
Is it pinking? I would suggest checking the ignition timing, which is easily done - do a search on this forum for instructions on how to go about this. Poor ignition timing can affect performance signifigantly.
I wouldn't run with out the air filter, the air intake is quite low down and in damp conditions I would be concerned with water getting in. - As well as dust, insects, grit which all damage the engine. As a compromise, you can get so called 'performance filters', or try trimming down the existing one.
Have you checked the throttle cable as John suggested?