The other day I was driving down the road, coming to a stop at a red light. I pushed the brake but kept going (this completely disoriented me for a micro-second). I realized after the disorient moment that the throttle was stuck and really pushed down on the brake which got me stopped, nearly rear ending the car in front of me. Once I was stopped (I still didn't turn the key off) the throttle was still stuck and the tires completely broke loose sending a cloud of tire smoke into the air. Then the throttle finally let loose and everything returned to normal. I drove home without another incident. Everything seemed OK. I haven't driven it since, not because I'm a scared to, I just haven't had a chance.You know it'll be on my mind now every time I drive it.

What could have possibly happened? Can any of you help me?

Sincerely,
Mike

 

First, major safety issue and serious cause for concern. Pull your codes right away and post them please. Next, was the floor mat pushing on your gas pedal in any way possible? Was the pedal or can it stick in any way while you are sitting in the car, engine off? Next will be the throttle body itself. You need to examine it for smooth operation and no oil like junk keeping the throttle plate open. Is the connector to the throttle body stepper motor on securely?

 

Also if it happens again, PUT IT IN NEUTRAL!!!!!!!

Definitely check your floor mats

 

Floor matts were no restriction but I did install a new throttle body on it a little while ago. I have probably driven it about 6 times since then. I'll make a serious and thorough inspection of this install I did. I never thought about putting it in neutral. Thank you for your input. I'll definitely check out all of this stuff before driving it again.

 

Plus, I'll pull the codes also and see what comes up.
Thanks again.

 

Why did you install a new TB?

 

I was looking for a better breathing motor. I installed the Vararam w/power duct, a ported MAF, a ported TB, LS6 intake, Melrose header system w/high flow cats and Corsa Touring exhaust. Plus a dyno tune and 3.73 gears.

 

Any chance of posting up the tune? Or privately?

 

I had a dyno tune done at a shop in Smyrna, TN. I don't know what type of Dyno it was. But, here's the results...
RWHP = 349.32
RWTQ = 348.97
I am probably not an experienced driver with this much power as a lot of you are. This car is a hand full at these power numbers. It can get down right scary if I'm not careful. I can't imagine a car running 500 HP and TQ numbers and up!

 

I needed to hunt this thread down, I'm not sure if it is the correct one as I thought there was similar discussion in the C5 section. Non the less it maybe be a thought. Read post #2.

http://forums.corvetteforum.com/c6-s...s-and-tbs.html

 

If theres a difference between the THROTTLE PLATE position and the Accelerator Position Sensor (accelerator peddle), the engine will go into reduced power mode and set a DTC. GM Throttle By Wire System is VERY reliable and has very almost ZERO problems like the one that your expierencing that is caused by a TPS system failure.

My guess is that the Accelerator Position Sensor (APS ) is not returning to the up position. REPLACE IT!

Check for something that keeps the accelerator depressed or a bad return spring in the APS Sensor.

BC

 

Can't believe you found it. Nice find. I always learn things here.

 

Are you sure you didn't get your foot on both the brake and gas at the same time? Not sure on an auto but it's fairly easy to do with a 6-speed if you're not careful about where you put your feet.

If your answer is no then think about this. Were you pressing on the gas enough to cause the power level you had while stopped. By this, I mean when you got it stopped the car was basically doing a brake torque. Were you pressing the gas enough shortly before you braked to actually be able to do that?

This was something that seemed to be totally ignored with the Toyota crap that occurred. "I was driving through a parking lot and as I went to stop in a parking space my car took off" was a typical story. Well, how the hell did the pedal get stuck down if the person was idling along until they stepped on the brake (cough gas) pedal?

So, If you were barely on the gas before the incident then it was likely 1 of 2 things. You stepped on the gas or the car has a combination mechanical and tuning problem.

Now, I'm quite certain the computer also compared the commanded throttle position to the TPS feedback so those tables linked above are not the only check for a stuck throttle. I played with it once and as soon as the commanded throttle position and TPS feedback don't match, the car goes into reduced power mode and will not produce much more than idle level power. The computer will retard the crap out of the timing and dump a lot of raw fuel out the exaust to keep the power level down.

Peter

 

After the incident was over, I thought about having my foot on the gas at the same as the brake. I even looked down at the brake and gas pedal immediately after it happened. The gas pedal looked a lot lower than the brake so I dismissed that idea. It is an automatic.

 

Done it before myself. Shoes.

 

Once you press the brake pedal down enough to actually brake the throttle pedal is no longer lower.

Peter

 

I don't buy this for a second...

to answer your question though: no, I can't help you except by offering this suggestion: when your car does this again, just hit the shifter to neutral. problem solved.

 

I'm sure it's something to do with your new T-body--If you don't have tuning sofware--try dis connecting your battery overnite and let all the stored data unload--Your LTFT's will have to learn out so it may run crappy for awhile--ALSO it could be in your tune---typically a "hanging idle" can happen with having too much "desired airflow" most likely in the 'in gear" table -- other tables that affect the throttle are found in the traction control section the "ETC TQ pedal redction "table can often cause a hanging idle as well as other ETC entries in this section--Setting this entire table to 100% is common--but some cars don't like it--When i see this I only go to 100% from about 1/2 way to the end of the table--
PS check all the TB elect. pigtails---- Also see if in the REST position that the TB is cracked open with eng off---which is important--
ALSO just remebered---the "throttle follower" table is often worked on with your mods--having it incorrect will wither cause it to die--or hang at cruise or idle--