Torque Converter Seems to lock up at idle

[mr5231]

OK, I am hoping someone can help me. I purchased a 67 Camaro at the start of summer. The car is equiped with a 700R4 and a rebuilt 350.

For some reason when the car idles in gear for more than 10 minutes the engine will die. At first I thought the carb was getting too hot so, I installed a spacer below the carb. Now the carb barely gets warm and I still have the same issue. Also, in the middle of summer with outside temps in the high 90's I can get the car to idle in neutral all day long, even at low RPM as low as 500. If the engine and trans are not fully warmed up I can get it to idle in gear as low as 700!! Once warmed up and the car idles in gear for a while it will stall. In order to get it to idle I have to raise the idle north of 1500 which, is crazy.

Can anyone help me figure out what is happening? It seems like the torque converter is locking up when it gets hot. Is that possible.? Could it me something else? Please help. I don't know what to do next.

Mike

[Fuelie Fan]

I think the fluid routing of the transmission in the valve body prevents this. Sure, you could have a shorted solenoid, but with no pressurized fluid passing through it, it wouldn't matter. I would look elsewhere.

[mr5231]

I replaced the solenoid. What else could it be??

[myclone]

Provided everything in the trans is built correctly you shouldnt have TCC (torque conv clutch) lock up capabilities in 1st gear which is what the trans should be in when at a stand still.

If somehow the TCC was engaging while at idle in gear the car should lurch forward against the brakes (you do have the parking brake set dont you!!) and die. Just like a stick shift trans would lurch/kill the motor if you dump the clutch at idle in 1st. Is your car doing that? I suspect not but figured Id ask.

If the trans is wired into the car correctly then the TCC disable should be wired into the brake lights so the TCC unlocks when the brakes are applied (least I hope yours is wired that way). If its wired correctly then does the car still stall after idling in gear with your foot on the brake? Even if something is goofed up in the trans the brake interlock should keep the TCC from applying as long as you hold the brake pedal down enough to turn the brake lights on. Try that and see what happens.

[mr5231]

I don't have a switch on the brake pedal for the TCC. The car does not lunge forward when it stalls. It just cuts out. Also, if I unplug the TCC (same as a switch) I still have the same problem. Remember, the car idles no problem in gear when it's cold or even slightly warmed up.

At first I suspected that the carb was getting to hot so I put a spacer under it which really cooled off the carb. It just gets warm now. The strange thing about all of this is that I can get the car to idle in neutal down around 600 RPM all day long even if it's hot out. The car will only stall when it is in gear. I would think that if the problem was engine realted that I would have the same problem in neutral. But, I could be wrong. I'm stumped. Help if you can.

[myclone]

If youre TCC isnt wired into the brake switch then how is the TCC circuit configured to drop out the TCC on deceleration? Do you have the TCC wired to a manual switch or an automatic circuit of some type? While I dont think the TCC is what your problem is Im trying to get an idea of how the trans is set up.

Is the trans a fresh rebuild? Has the car had this problem ever since youve owned it or did it just start recently?

Just to reiterate what I said above if the TCC clutch applies then the auto trans is just like a stick trans. In gear at idle if the TCC applies the car will try to move just like letting the clutch out on a stick trans at idle. It sounds like your car isnt trying to move from your description so an educated guess is that the TCC isnt being applied (or at least isnt being applied completely). An internal trans leak could cause the TCC to partially apply just enough to drag the motor down once up to temprature but in all honesty I would think you would have noticed the car try to move a little just from the interia of the rotating parts beforeb the motor dies.

[mr5231]

I was told my trans is set up only to lock up in 4th gear. Therefore, I simply have it wired to 12 volts. The trans has about 3500 miles on it. The problem did start recently. The car doesn't move forward at all when it stalls however, it does feel like something is draging the engine down.