Hesitation on take off

I had to take my wife’s car into the shop today for a hole in the EGR tube. Upon inspection at the shop the main ground wire was melted, which ended up popping the main fuze, which killed the car. They repaired the tube and the wire and replaced the fuze. On my way home, however, I noticed that her car was very slow to take off. I had the air conditioner on and thought this might be it, so I turned it off. This seemed to slightly fix the problem, it is not as sluggish as with the AC on, but does not seem to be as quick on take off as it was before. Her AC is also blowing out cool (not cold) air. It seems to run fine once it gets going. Any idea on what could be causing this? Could the AC just need a refill? There is no service engine light on.

I also wanted to add that the car does not have a rough idle, nor does it sound strange. It actually sounds way better now that there is not a hold in the EGR tube.

Take it back. Any shop that could melt the main ground wire while inspecting the EGR tube (how the heck did they do that? 400W worklight?) could have admaged something else.

NOTE: the AC when on will always have some effect on a small engine. It takes its power directly off the crankshaft, and that adds a detectable load to the engine. AC also has to “get going” to go from cool to cold. It works by “chilling” an “evaporator” with rapidly expanding compressed refrigerant. It has to run for a bit to get the evaporator chilled. The cabin air is then run past the chilled evaporator coil and its heat is withdrawn by the coil. My guess is that the difference in the time it takes to get cold is due to “post-repair hypersensitivity”, where we become hypersensitive to things after the repair that we didn’t notice before, but it’s also possible that a recharge could help.

Thank you for your quick response, however, I would like to apologize for the wording in my original post. What I meant to say was that when the shop popped the hood they noticed that the main ground wire was melted due to the extreme heat of the EGR tube. The insulating material of the EGR tube (some sort of fiberglass mesh looking stuff) also had a hole in it. They thought that it looked as if the ground wire’s lack of insulation caused it to repeatedly arc against the EGR tube and eventually burned it’s way through it. I hope that helps to explain this a bit. Also, my wife complained of the warm AC yesterday, right after she informed me that her car was hesitating on take off, so I know it’s not the “post-repair hypersensitivity”, although I have experienced this before. I thought that the dime size hole in the EGR tube was the culprit for the sluggishness, however, this does not seem to be the case. This is why I brought up the question of the AC, since the car seems to have more problems with it on than off. Any other suggestions of what could be causing the hesitation (complete lack of response when pressing the gas pedal, whether it’s to the floor or just a bit) would be greatly appreciated. I’m just trying to think of what could be wrong other than a MAF, Idle Air Sensor, or any other $200+ fix. Thanks again for your fast response, and I couldn’t agree with you more, if a shop breaks my car I’m the first to say something.

Have a knowledgeable “car person” who has nothing to gain give the car a spin and see what he thinks. I know that I can test drive probably 80% of the cars made and tell you if things are right. A test drive for me of a real exotic would just be that ,“fun for me” but everyday cars, you should be able to find someone to drive it and give a report.