Scary moment today.... was in traffic and when we started to move i pressed a little to move through traffic (maybe halfway through the pedal) but when i lifted off I felt the car just pull away... so i immediately threw it to neutral and the engine just revved through like a turbine and just as i was reaching to turn off the ignition, everything went back to normal! WTF!

Any thoughts?

 

Sounds as though the throttle jammed open- quite alarming when such happens.

Suggests either a problem with the throttle itself or more likely, a problem with the throttle cable.

 

I've seen this happen at the connection where the "cup" on one of the cables was sticking on the ball, could be dirty, corrosion... I always put a dab of grease in there to keep things moving freely, on all of them, not just the throttle cable.

 

I promise you guys, this was not a fun experiment :-D

Will check the connections at the intake...

 

The one time it happened to a friend of mine 20+ years ago in a low mileage S4, he was coming into turn 5 at Road America. Thankfully he pushed the clutch in and killed the ignition fast enough to stop on the out road. In the paddock is when it was discovered one of those ***** was galling preventing the throttle from returning back.

 

Any chance I damaged the engine or does it have rev limiter?

 

Take a look at Stuck Throttle (in the Mountain Twisties, no less!).

 

Thanks Ed, sounds like you and a few have had this little adventure. I am now seeing some oil residue around the front of the engine in the recess under the intake/behind the the Thermostat line as well as on top of the oil pan and on the left side lower engine cover... not sure if this was from before and i just notice it because i looked or something broke with that high rev.

 

The engine management has a soft rev limiter in that fuel is cut off from the engine at the proscribed set point which for the GT is 6700 rpms or so. The fuel does not kick back in until the revs have dropped about 500 rpms and by that time I am sure you would have killed the ignition.

 

Fingers crosses Fred... as fixing anything on this car here is a mission!

 

I had this happen once after I had "fixed" my cruse control. If you don't use your cruse control you might want to pull that cable off.

 

Sounds like a ball sticking like posted above.

I had something similar in my 81 happen that wound up being some wires from the TPSs getting jammed in the throttle mechanism on the throttle body.

Might want to use a mirror and check for any loose wires as well.

 

Worn quadrant shaft and bearings will catch the linkage and hold it open too.6.6.0

 

Actually pretty common.
Most of the time, the cruise control cable sheath is broken loose from the plastic that goes into the quadrant. The sheath hangs up in the edge of the plastic and holds the throttle open before it "pops" down in.
A couple of cleverly attached tie wraps will keep the sheath inside the plastic end.

 

I had this issue with revving high and lurching forward, and I pulled my cruise control cable off as some suggested- and that helped a little, but I still had weird intermittent over revving. Then my wrench guy replaced that little throttle motor regulator (idle regulator?) that I think sits in bw the LH and the throttle. Problem fixed and I have reattached my cruise control even tho I never use it.