corsa warning light and loss of power?

I have a 1.0l w reg corsa B. I often have to use the accelerator to start the car and then in the first mile of driving the car will make a really loud humming noise as I accelerate and will slow right down to about 5mph or less, even in first gear, it rocks back and forth and then just before it clears itself it violently jerks before suddenly revving itself up. Sometimes stopping and restarting the car solves this problem, but not always,

I then have the problem of going up hills where the engine management light comes on and I have to go down the gears to just about make it to the top, and also when I am maintaining a speed of about 40/50 and trying to accelerate further(doesnt often drive much faster than this without the light popping on) the light will not go off until I have my foot off the accelerator for a while, not possible when going up a hill though!
And when the light comes on you can feel the car pull back and lose power.
It is ridiculous and extremely expensive.
I have changed:
Oil filters
Fuel filter
Idle control sensor x2!
Cleaned the hoses that can be got to.
I think thats all, maybe more, its hard to keep track!

Also when I clean out 2 black hoses under bonnet, (not sure what they are called) but a yellow/white slime comes out of them? which to my knowledge, shouldnt be there as it is only meant to be air that goes through them

I dont want to spend too much more but cannot afford a new car and surely wont get a lot for selling the corsa in this condition

Please can someone help me

sarah
February 2011