Humillo of the steering wheel when starting in Opel Astra F

First of all greet and thank you in advance.

My problem is as follows, the car is an Opel Astra 1.4i of 92 and I have it for only 2 weeks, the first week when it started it perfectly, but for 3 or 4 days when I started it costs it and it comes out humillo and smell to burned from the steering wheel. The latter times when starting it is like if the release was very low and goes out, but as soon as it starts and then the release is stable in 1000rpm.

And it is not the subject that the engine is cold, since being the release and everything perfect at 1000rpm once working, as I do to turn it off and start again, it costs it again to start.

I do not think it is due to a change of spark plugs that I have made 5 days ago, I have thought it could be something of a chamuscado cable causing short or the starter engine.

But as I am very lost, I prefer that you give me your opinion of what could be.

By the way, once the car is already working perfectly.

Friend first welcome you to mechanical manuals, second your problem is the starter engine itself, perhaps it is making a short internal circuit or it is overheating, you must take it out and review it outside, an important detail is that the start is only composed of two cables one is direct battery current and the other is the current of a chapa that is responsible for exciting the solenoid, the earth is made It is not very difficult to check, of course you must disconnect the battery first, the smell of chamuscado cable is due to overheating of the same start, luck and warns how you are doing.

Thank you for the Kike Council, tomorrow I will disassemble it and I already tell you.

(I have been out of home 1 week and I just arrived hehe)