i have a 74 Nova 350 with a TH350 that has been sitting for 6 years, i just got it running and back on the road, engine idles fine, drives and shifts great but when i first put into gear or i come to a stop sign or light i have to hold the brake with a lot of pressure and keep my foot in the gas to keep it running. it is like the transmission is not disengaging when in gear and stopped, could this be a vacuum modulator or a vacuum issue? if not do any of you have an idea what it could be?

 

Shift it into neutral at a stop, see if that is the issue.

 

Bad vacuum modulator would keep it from shifting. Sounds to me you have an idle under load problem with the engine not a transmission problem. The transmission does not "disengage" when you are at a stop, the slip in the torque converter allows it. You need to fix the engine idle under load, right now at a stop you are pushing too hard on the gas to keep it running, effectively power braking. What is your in neutral idle speed? Should be around 750, try raising it a bit and see if the issue goes away.

 

thanks for the info, i must not have gotten all the bad gas out of it when i was setting carb and idle, after a little but of driving, i rechecked it all and found the carb was not adjusted right, reset idle screws and messed with the idle (no tach yet) and it seems to do a lot better. i will run for a while and recheck it