problem with corrado 16v

[davidw7 10]

i own 1995 volkswagen corrado 16v.problem i have is:every time i start it hums up and down as if its about to turn off and it does turn off if i sit there long enough.so,i drive out in it but every time i clutch to change gear it almost cuts out(it did once or twice)and if i come to a stop sign it will either hum up and down about to turn off or it WILL turn off or if im taking a left/right turn and i clutch to go into 2nd gear most times it will just turn off as the car is taking the corner!!!!!! it doesnt chuck and cut out,it just turns of.so i have to let it roll around corner and start it again!!

 

so,to avoid this first problem,what i do now is start car,turn it off and start it again.this time though it always starts over revved.the hand does be up at 15 or 20 on the rev counter without me touching the pedals.it continues like this as i drive along the road ,each time i clutch to change gear the rev count flies up.this will last for about 10-15 mins and then it will go back to driving normally.

 

if i go any where and leave car for 15-20 mins and come back it starts and goes fine but if i leave it for a few hours its just a repeat of the above.

other times if im sitting in car waiting for someone outside a shop out of nowhere the car will just hum up and down for a minute or two and turn off itself!! then sometimes when it starts to hum up and down about to turn off,if i turn on the lights/heater and the car powers back up and when i turn of lights/heater it goes back down again.

i thought it was the battery,so i bought a new battery but it just does the same.if anyone can help at all i would appreciate it.

thanks,david.