Hello and thanks for reading, this is my first post of many.

I'm experiencing problems with my Mk6 1996 1.4 CVH Escort. She's a beauty, and only cost me 250, apart from the listed issues (which I was aware of before buying), it's a good car, and I feel it can be saved.

Had the car a few weeks, and struggling to diagnose a problem.

Pulling away with gentle throttle, it feels very flat, and sluggish. Put your foot right to the floor and after a slight delay it's off like a rocket. (I know this sounds normal! but it isn't, something is definitely wrong) It's quite strange, one second it's flat and feels like dying, then it's fit as fire, but with a strong smell of petrol.
I've replaced the HT leads, and have a fuel and oil filter ready to go on during an oil change tomorrow.
The temperature sensor has detached from the block, so I don't know what the temperature is at any time. I'm guessing this might help once fixed? Any idea how much and where to find one? Not sure I know what to ask for, it's just a long piece of wire and I can't see where it goes under the engine.
Got a Haynes manual on the way. As you can probably tell, I'm reasonably new to this, I've always had an interest but never my own car to work on! Well prepared to get stuck in.
Thanks in advance, I hope you can help me!