major car trouble! mechanics cant fix!!

I recently purchased a 1995 hyundai excel sprint. I have owned it for 5 months and have not had any trouble with it up until now. Driving home from work the car started to loose power at an extreme rate..even with my foor flat on the accelerator. After a few pumps on the accelerator the car surges forawrd at a powerful speed without my control. It has become a danger on the road for me..so I decided to take it to a mechanic. they had it for a day, sent to an auto electrician, as they claimed it was a computer problem. Unfortuantley,the auto mechanic could not find any problems with the on board computer.
I then sent it to a certified hyundai mechanic in my area...who hooked it up to the computer and claimed it was the accelerator sensor and a repair cost of $750 dollars. They fitted the new part...and to my dissapointment...did not rectify the problem. The mechanics gave me a loan car and offrered to keep my car and go through it to find the problem. It has now been nearly eleven days...the mechanics have changed plugs,cleared out the fuel filter, checked all other sensors, looked at the fuel injection, harmonic balancer,motor compression and exhaust.
I have rang them every day to see if there has been progress but they can't find whats wrong with the car. I have searched all over the web for answers but can't find any!! I was wondering if there was anybody who had expereinced the same car trouble and if they knew how to go about it.
These people that build these cars must know how to fix them!! Please message back if anybody has a clue on what the problem could be.
Thanks!!

Did you find out what was wrong with it?

well i experienced the exact same thing but not on my hyundai it was on a ford focus and i did all the checks like the mechanix did for you and after i spent like 300$ on new parts i found out it was the tranny.. it sounds like ur tranny might be going out cuz the power surging in the car. my car would loose all power and id give it more gas and then it would jerk forward at a high speed and then loose all power again and so on and so forth.. so im not saying it is your transmision but id look into that..

Dana Torres

Hi Sarah, I had an old ford falcon that was starting to do strange things. 1st thing to do, is check every electrical connection in the vehicle, lucky enough it was a wire off a temp sensor, heard of another one that was a small bit of corrosion in the main wiring loom connector. A decent auto electrician should be able to find what it is, let me know what happens, thanks tim