Hi Folks,

I have owned my '91 vette for about 6 years now.  I bought it used, about 47K 6speed manual  Now has about 59K miles, summer car in NE Ohio.   Mine has the luggage rack option too making it pretty unique, LOL! 
Love the car. 

The only problem I have had with it was quite scary.  I was driving in 6th gear on highway about 70Mph.  I think
I had cruise on too, I cannot recall due to my post traumatic stress, LOL.  Traffic not too bad I was just minding my own business with the top down.   All of the sudden my Red Vette Red lined for absolutely no reason at all.  As if I suddenly shifted into 1st gear going 70!.  I thought the engine exploded spontaneously for no reason.  It was in 6th.  I quickly shifted to neutral which stopped the reving and
then pulled off the 4 lane highway. 

I had it towed to a place nearby who didn't know what it was.  I drove it from there after it sat for a while, and it happened again at 35Mph this time. Tried to restart.  It did this time.  Drove a little further to a gas station down the road.  Almost got there, but it stalled out again.  Pushed it to the station.  Went to a bar across the street for drinks waited for a ride then had it towed to dealer. 

Turned out the root cause of the issue was the computer.    It just blew up or something.  About a $600 repair with labor. Then it has been fine since. 

It almost seemed like a safety issue to me.  I never thought a car could do that, spontaneously redline for no reason at all on a manual 6 speed.  It didn't go faster, if anything it dropped speed.  But it sounded like I shifted into first with manual transmission into 1st on purpose.  Horrible noise you have no idea; I will never forget that sound.   
The computer must have done something with the fuel injection or something?  Totally bizarre a computer could do that. 

Anyone seen anything like this with your C4 ?? 

If it happens to you, don't panic; just shift to neutral and pull over.  It may not start up again for a while, but you can have it towed to a dealer and have your checkbook ready.

Later,

- Ken

The only explanation that I can think of that would have the revs increase and the speed decrease, would be the clutch slipping, (or it somehow went into neutral). Otherwise, it defies the laws of physics And if it was in cruise control at the time, that might tend to make it more pronounced. Was it in cruise control both times that it occurred?

I think you have a bad clutch.  My 1993/6 speed's clutch started slipping like that around 60k miles.  Just yesterday while doing 70 with cruse control on, the engine reved to 4000+ out of nowhere. 

|UPDATED|5/6/2015 8:47:08 AM (AZT)|/UPDATED|