Help! Engine shuts down or loses power at 45

[Paul Douglas]

I have a 2002 Coupe with 120,000 miles that has always run perfectly. Took it in to my trusted shop and had new rotors, calipers and pads installed. All is great with brakes now, but it seems to have gone into a "limp" mode. It starts to shut down above 45 mph and just runs about 50 max.

I essentially am driving a beautiful, high performance "Yugo" now. It's like a computer has told it to go just 45-50 and stay there. Starts perfectly and runs great to that speed and no more. It was perfect before I left it for brakes, and that shop can't figure it out either. It's at the Chevrolet dealership now, which makes me shudder.

Any ideas what is going on? Anyone ever had the same experience? Thank you.

Paul

 

[Paul Douglas]

Engine power shuts off

In my preceding post, I neglected to mention that there are no codes thrown, either Current or History. The engine starts and runs perfectly, as does the transmission, Until you get to forty-five mph. I could drive any distance with no problem noticed if I didn't exceed 45. No one here knows whats happening. I've gone through my Factory Service Manuals with no hep. I'll bet Hibb H. knows what's up---if he is looking at this. Help.

 

[Paul Douglas]

Limp mode

I finally found out what the problem was with my Corvette. After the shop that usually cares for my car (a normally reliable, well equipped shop) couldn't fix the "limp mode" that my car had had gotten into following the replacement of the braking system. They recommended that I take it to the Chevrolet service department for diagnosis. They said their equipment couldn't read any codes, and the DIC never did show any codes of any sort.

Took it to Peltier Chevrolet in Tyler where it rested for three days. Had several phone calls from their technicians requesting info on what led up to this problem; like have you ever had any problems like this in the past? My answer was never any problem of this type.

Finally got a call yesterday from the shop manager who was laughing, and tickled to get rid of this problem. He said they had connected a diagnostic instrument to my cars computer port and had driven it. It showed that the front wheels were rotating about four mph differently than the rears, which caused the car's computer to throw the order for the engine to go into "limp mode", not allowing a vehicle speed over 45 mph.

Turns out that the shop that completed the brake upgrade, had taken the tires and wheels to be cleaned on the insides before reinstalling (at my request). Whoever cleaned them, brought them back to my car in no particular order. Someone reinstalled them without looking at the sizes and installed the front 17" in the rear and the rear 18" in the front. Believe me it was unnoticeable, by me or their shop or Chevrolet for a total of six days. Everyone just assumed that this Corvette had one of the famous Corvette electronic hick-cups and looked for something complicated, when it was very simple.

Chevrolet swapped the wheels around, checked the brake work that was done (my request also) and case closed. Car perfect again. Also re-learned another lesson. Start with the basics and don't assume the worst. We all thought computer problems, and it was "stupid problems." The bill from Chevrolet was $170 and paid by the first shop.