Today my 2005 Trailblazer LS went out of control. I stopped to let my wife out of the car. Once she was out I turned sharply so as to drive into a nearby parking slot. The vehicle accelerated way beyond the gas pedal's position. I slammed on the brakes but the brake pedal would not respond. The Trailblazer jumped a small curb, ran through some bushes and then smashed into a small tree before stopping. I then took it out of gear. The engine returned to normal speed. I was able to back the car up, park it and then let the motor idle. Not surprisingly the front end is damaged, but luckily I did not hit anyone or any thing other than some foliage.

I don't know if this is related but the Trailblazer had been showing a check engine light for about a week and a half. Also the engine was intermittently sluggish, hesitant to accelerate and even dying once or twice. I scheduled repair time. Unfortunately the light which had been on for a week at that point, turned itself off on the way to the shop. The computer diagnostics indicated dirty fuel injectors, which were cleaned. Seemingly unrelated.

Check engine light is on. When I went to read the code, it says cylinder 2 is misfiring. So, this can be a problem with pretty much any system in the car. Most probable problem would be an electrical problem with the ignition system. But technically it can be a fuel pressure problem, vacuum problem, exhaust problem (o2 sensor), electrical problem (sensor or computer), engine problem (bad seal, etc.)

First thing I did was to spray the hoses with starter fluid while the engine was running. This will tell you if it is a vacuum problem (bad hose), because if there is a leak in one of the hoses the engine will jump when it sucks the starter fluid into the engine. Well, the engine did not jump, so I eliminated that.

Then, I swapped out the coil/spark plug from the second cylinder to the third cylinder to see if it would read a problem with the third cylinder now instead of the second. I reset the check engine light so it is now cleared. When I got the light again, it says I have a "random cylinder misfire." So, that pretty much tells me that it is not a problem with my coils and spark plugs.

I read the fuel pressure and it read 80 psi. Which is good.

So pretty much I have no idea what the hell is wrong with this stupid piece of crap. I spent hours trying to figure out what is wrong, but I guess I have to give in and spend like $500 on a mechanic to figure this problem out for me.

I feel the same way about this truck. I spent a lot of money to get a newer "nice" car that would last. But, I have had more problems with this piece of junk that has 50,000 miles on it, then I did with any other beater I drove before it.

I have had $500 cars that lasted me 4+ years and had less problems with than this truck.

I'm lucky to be alive!!! My Trailblazer accelerated to high speeds on icy covered roads in a matter of seconds. I was traveling approx. 33 mph when it took off like a bullet, spinning me into the oncoming lane, back across the road and into the ditch. I hit a sign post that snapped right off. While lodged in a snow bank the tires kept spinning, the rpm's were high and the only way to stop this was to turn the ignition off. It's at the dealership now. I will never drive this vehicle again even if they say that they fixed the problem. I only have one life! I've seen this problem reported before with no resolution from Chevrolet.

The Trailblazer will accelerate by itself without the accelerator pressed nor the cruise control acc. on. I had to stand on the brakes and shift into neutral to keep from having a wreck, I took it to the dealership. They could not reproduce the problem so of course they sent me on my way. After having repeated this 8 more times over 2 months I took it to the dealership to be fixed along with a medley of 9 other problems. IT is still at the dealer, but GM is saying they cannot reproduce the problem, so I am out of luck....