Vehicle is a 2004 automatic coupe in beautiful shape with 32.000+ miles. Have performed all the common fixes (thanx to this forum) and the car has been running beautifully for the last two years. Last Saturday we went shopping and parked the car in open sun on an asphalt lot in 95F heat. Came back after approx. 45 minutes shopping. Turned the key and the engine started quickly but instantly climbed to 3,200 RPM. My feet were flat on the floor with no pedal contact. It was quite a roar due to my MagnaFlow exhaust. I turned the ignition off in a panic, waited around 30 seconds, and tried it again with the same result. One more attempt a minute later resulted in the same screaming over-rev. What on earth's going on? Decided to try it once more before calling a tow truck. On this fourth attempt everything was fine. The engine started instantly and idled fine. We drove home without incident. Started the engine a few times when we got home but everything was fine. Has anyone experienced this? Any comments would be greatly appreciated as my faith in the car's been shaken a bit.

 

How old is the battery? How badly corroded is the ground lug on the end of the battery ground cable? Have you seen any glowing of the "battery light"? What I am getting at is that this sounds like an electrical/electronic problem. SOMETHING caused the ECM to command the throttle body and injectors to do this. (If it was, say, just a throttle body sensor, the injectors would not have been commanded to provide enough fuel to do this, would it?) Why would the ECM do this?

Other than the battery and electrical issues - the pedal sensor would be my next guess. If the pedal sensor reported that you had your foot to the floor, with the front wheel sensors not indicating motion, the ECM limits engine speed to (I THOUGHT) 4200 or 4400 RPM.


EDIT: Here is a thought. My SECOND Crossfire (the Graphite one below in the photo) did something twice in 77000 miles that was similar to what you had happen. IN fact, it was the SAME THING. I'd left the car on Highway 180 in North Georgia and went for a 10 minute walk in the woods. I returned and started the car - and headed down hill - soon I realized it was accelerating -I pressed the clutch in and the engine went right to 4200 rpm or so. All I could do was turn the key off. I then turned it to "ON" and let the clutch out, it did it one more time going down hill - did not do it again until about three months later -when it did it at the EXACT same spot again!

Conditions: 85-90F, high humidity, less than 1/2 tank of gas, sat for maybe 10 minutes, went down hill upon startup, on a Saturday both times. I never saw it do it again, and I never figured out what it was that made it happen.

 

Thanks for the comment. It's consolation to know I'm not alone. Battery's fine...I keep the posts spotless. I also thought it could be an errant signal from the ECM, possibly due to the rise in underhood heat while the car was standing on hot asphalt after a drive on a hot day. My 2002 Town & Country minivan would run fine with a cold engine, but then quit when it warmed up. I replaced the ECM which cured the problem.

 

Had the same issue earlier this summer so I did a throttle reset, VOILA, all fixed and haven't had a repeat of issue since.

 

I know people generally 'scoff' at things like this BUT, EMI can and does do very bad things to electronics all the time. Having this happen to PG's car at the same location, may help determine if EMI caused his event. Just my $0.02 cents worth.

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You know that is only one of the reasons I wear a tin foil beanie.
Shush, I got to go and hide, those men in white coats are after me again.

I'd say throttle pedal or throttle body issues.

 

Hide Dave! You can run but they are younger and have more stamina...


My suggestion is a result of PG's car experiencing the same thing at the exact same location, at two different time periods.


And there was that time when my car was flashing the fog lights when a B-1 bomber was doing touch-and-go operations on base (restaurant was right there within 250 meters from the base flight path), and it has not happened again since.


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