Mitsubishi Repair: lancer GDI major engine problems, second hand car, brain box

Question
ok, i bought the car second hand and took it for a tune up. two days before taking it to get the tune up, the battery died and the person driving the car jump started the car. the next day the CD player refused to work. What the mechanic told me while doing the tune up is that the electric surge from the jump start cause the brain box to be damaged beyond repair. He cleaned injectors, changed sensors and i bought  new brain box for quite a bit of cash. the car never drove as well as when i first bougth it since. subsequently the gas pump sensor began to malfunction and one day stopped working all together 9 check light on, unable to accelerate when foot on gas, slow start them sudden surge of power) bought a new on of those too. Throughout this the car has maintained a shuddering and stuttering (almost as if its about to cut off) if idling for under a min or so. the intensity of the shuddering varies from time to time. Please tell me what can be causing this? Is the mechanic robbing me blind? He thinks the shuddering is a malfunctioning throttle body (more money!!!) And can a prior electrical problem in the car (second hand car) be the cause of all my frustartion ( and the car not being able to survive the jump start.)

Please advise.

Answer
Abigail: I am sorry for your trouble, but sadly if you do not jump start these cars right, all hell can break loose in them. I think you could have your car coded, that will rule out any problems with other sensors or the computer. If you got an AutoZone close by, they will do this for free. If you do not trust this mechanic that is working on your car, get a second person to check the car over. Explain to the second person that you just want a check over, then take notes and then check out what the two are saying to you. I have to say that shops and mechanics alike don't always treat women so good. I wish it was better out there, but it isn't. With this tune up did you get new stark plugs, stark plug wires, distributor cap and rotor too. New air filter and the such. You say he cleaned the injectors, changed sensors and you bought a new computer for your car. But nothing of the tune up, which would be the stark plugs, stark plug wires, distributor cap and rotor. Are you sure you got the right computer(brain box) for your car? It could be the throttle body, well that sensor but that is why getting the coded on your own; you would know what sensors are weak or bad. You don't say how old this car is, so I can only guess here. But still I understand how upset you are about all this. I think you need that second person to look your car over, because the first one could be robbing you blind. Because of how these male mechanic treat women because they know a woman does not know a lot about cars. I have had guys do this to me but I put them in their place in a heart beat. Now I carry my own tool and a cell phone, if I can not fix it out on the road well I just get the car tow home. Who told you that your car needed a fuel pump sensor? Have you ever had the fuel pump it's self checked? Would you please write me at my email address... and tell me all the things this guy did and what he didn't do? Because I would really like to know and you can only write so much on this site. My email address is (oppedal50@yahoo.com) something sounds fishy here but if you would rather not write me, at my address. I will understand that too. Anyway, get that second person to check the car out. See if you got that tune up I told you about, your car might just need a tune up, they run much better after that. Have the fuel pump checked, it is an easy test and it would show if it is working right. You know don't you that the fuel is what keeps the fuel pump cool, if you run your tank down to empty all the time. With time you will cook the fuel pump, I know with high cost of fuel of late we are replacing a lot of fuel pumps. Does you check engine light come on inside the car and does it stay on? Was that light on after that jump start? Again get that car of your's coded to see what it is really telling you. I mean your mechanic could be pulling the wool over your eyes or he could be tell you the truth. But do you get to see the print out from these codes? So please keep me posted on this as I want to know. I do hope this helps some and good luck! Linda