I have a problem in which the throttle will stick open only under one very specific circumstance. When the vehicle is stopped and the throttle is opened very gradually, everything is fine. When vehicle is moving, there is no problems at all, BUT: when the vehicle is stopped and the throttle is opened aggressively, it will stick open momentarily (until about the first shift). While it is stuck, the accelerator is not depressed, and I can try to lift it up with my foot but it is clearly not stuck. I can stop the sticking by shifting quickly to neutral, which seems to allow the throttle to close. Since the linkage is not binding and the pedal itself is not stuck to the floor, and because shifting to neutral stops the problem, it seems like a trasmission problem (?). My only guess is the modulator, which I will replace this weekend. Has anyone even heard of or experienced this before.

Forgive long post, vehicle specs below.

67, 350ci, TH350, Edelbrock 600 cfm, rod linkage, B&M Pro Stick

 

I'm having trouble imagining this... How can you stomp on the throttle gradually? How can a vehicle be stopped until the first shift? Are you saying that when you stomp on it, it will stick till it changes to 2nd gear? If so check your motor mounts...Eng is probably moving and causing the accelerator to bind. Just 'cause the pedal is not stuck doesn't mean the linkage is not. When you shift to neutral, the Eng re-seats itself and presto no more bind.
Leave the trans alone!!! Your problem is not there!
Mark

 

from the description i think id look at the carb cable and linkage area and also be sure you have a return spring of sufficient length and strength to pull the throttle plates closed. it almost sounds like you may be missing this part. check it out and get back to us kurt

 

Does your 67 have linkage or cable? Since you suspect it also having something to do with yourtranny try disconecting the kickdown lever. Check if its working freely. Do your test your doing now with it disconected from the carb.