69' camaro tranny problem

We are having problems with the car staying in gear, i typed this at another forum:

We had the back end lifted up, and when we started the car and put it in drive, the back wheels were spinning, i would have to say approx. 15 MPH. This is at idle BTW. The car did run kinda rough when in drive, but since the tired were spinning, it didnt make much of a difference. Also, i turned the idle down, and the car acted like it wanted to stall out.

After the car was back on the ground, when putting it in drive, it just wanted to stall out again. When we put the car in reverse, it seemed fine, but in drive, stall. We had no problems backint it into the garage (cept the floor was a little wet, and the tires started spinning) but when we tried to straighten it out, like i said, it would just stall out.

What do you guys think is the problem?

Also, the idle is set so high, that when we put it in reverse, the car goes about 8 MPH on its own.

Ok, im guessing from the description that your car is an automatic.

The behavior you are describing sounds normal to me. Anytime that the tranny is in gear, and the brakes are not being held, the tires will spin. and the car will move. The reason is that while a manual tranny completely disengages from the engine, an automatic is always coupled to it with the torque converter.

The idle speed should be set with the tranny in park or neutral, not in gear. If you have been setting the idle speed with the intent of not having the tires moving with the tranny in gear, then your idle speed is far to low, and that is your problem. With the tranny in park or neutral, your idle speed should be somewhere between 800 and 1200 rpms depending on the engine and cam options.

What is your drivetrain setup? engine, tranny, and mods???

Ok, im guessing from the description that your car is an automatic.

The behavior you are describing sounds normal to me. Anytime that the tranny is in gear, and the brakes are not being held, the tires will spin. and the car will move. The reason is that while a manual tranny completely disengages from the engine, an automatic is always coupled to it with the torque converter.

The idle speed should be set with the tranny in park or neutral, not in gear. If you have been setting the idle speed with the intent of not having the tires moving with the tranny in gear, then your idle speed is far to low, and that is your problem. With the tranny in park or neutral, your idle speed should be somewhere between 800 and 1200 rpms depending on the engine and cam options.

What is your drivetrain setup? engine, tranny, and mods???

THe engine is a 350, and has a th350 tranny in it.

We really dont know what has been done to the engine, but we were told that it has 12.5:1 compression, and .490 lift.

Why would the car move though, i mean, if you let the brake off, the car will start going at about 15 MPH, that isnt normal for any car. I know it is normal for the car to move, but not that fast.

WHen the brakes are hit, the car dies, because the tired are trying to turn, but we wolnt let them.

If we turn the idle down too low, the car dies.

We are adjusting the idle with it in gear so we can get it to keep running with it in gear. The car has to be at around 1200 RPM to stay running when put in gear, if not, the car just pushes foward, and stalls (like someone let the clutch in too fast in a normal car)

When we tired to get it back in the garage, it kept stalling out.

Im no specialist, but wouldnt the converters on the car at least have a stall higher than 1 RPM ?

well, it sounds like you have a race car on your hands, i was thinking street car. The fact that you have a high performance engine will contribute to the fact that the car moves so fast in idle.

That being said, i think you should tune the engine in neutral as i said before, and then if it still stalls, i would point to a transmission problem. most likely in the torque converter. Im trying to think of what would happen if they installed a lockup converter in that tranny, weather it would never lockup, or if it would be locked all the time. also, check your manifold vacume when its at idle, and when its in gear. There may be some sort of signal vacume that is dropping to low and stalling the engine out.

allright, did you get the race car from the engine specs, or how the car acts in gear?

The engine did look like it was set up for racing, high intake on it, ect.

Wow 15 without gas pedal.....your car just really wants to go. It seems like there would be a happy median between not stalling but not going 15mph.
wierd....

Wow 15 without gas pedal.....your car just really wants to go. It seems like there would be a happy median between not stalling but not going 15mph.
wierd....


thats just an estimation, we dont have the speedo connected.

Anyways, there seems to be no happy place, it is either trying to stall, or we have to wrench the brakes to keep it from moving.

I dont know.....sorry,
good luck, hope you fix it.

Sound like something with the fuel entering is set wrong, just a guess

Sound like something with the fuel entering is set wrong, just a guess


what makes you say that?

I know this isnt the problem, but we did put the medium grade octane in the car, cuz the 115 ran out, the car is knocking kinda bad, were trying to find a place around here that sells the gas.

EDIT** Just to let you guyds know, the car is running very rich.

DO NOT RUN MEDIUM GRADE GAS IN THAT CAR!!!!!!!!!!!

It is EXTREMELY dangerous. and the detonation may be severe enough to break a connecting rod and blow the engine. the race car conclusion i got is from the specs of the engine. there is no car that is made for the street that runs a 12.5 to 1 compression. Even the hairy nasty, street legal race car known as the 1969 Z28 with the DZ 302 only had an 11:1 compression, and that was with leaded gasoline.

I can almost guarantee that the midgrade gas you are putting in that engine is making it stall due to detonation. Get that gas out of the tank, and run the 115 octain gas and see if the problem goes away.

Good call 89IROC&RS, took the words out of my mouth.

DO NOT RUN MEDIUM GRADE GAS IN THAT CAR!!!!!!!!!!!

It is EXTREMELY dangerous. and the detonation may be severe enough to break a connecting rod and blow the engine. the race car conclusion i got is from the specs of the engine. there is no car that is made for the street that runs a 12.5 to 1 compression. Even the hairy nasty, street legal race car known as the 1969 Z28 with the DZ 302 only had an 11:1 compression, and that was with leaded gasoline.

I can almost guarantee that the midgrade gas you are putting in that engine is making it stall due to detonation. Get that gas out of the tank, and run the 115 octain gas and see if the problem goes away.

Were not sure if it has 12.5:1 compression, but someone said that even with flat pistons, and fullie heads, the compression is still at 11:1.

Also, it stalled out, and did the same thing with the 115 octane gas in it as it did with the mid grade in it.

a little update, but were pretty aure it does have alot of compression, we put a spark plug from y dads old chevell e in the car (it was only 1/16" bigger) we slowly cranked the engine, and after a few turns, we started it up.

It kept on stalling out, but we thought that it was cuz of te choke.

Anyways, we took the spark plug out, and we found that the piston made the gap from 35 to 0.... so we know that the piston is mostlikely comming up above the deck.

have you pulled the other plugs to see if they have any damage? with that compression if you are running plugs that are too "hot" then the electrodes may have burned away in the high compression. causing a lack of power leading to a stall condition.

have you pulled the other plugs to see if they have any damage? with that compression if you are running plugs that are too "hot" then the electrodes may have burned away in the high compression. causing a lack of power leading to a stall condition.


nahh, the plugs are all fine.

They are badly fouled though, because we have a carb problem.