jman1

just did an engine/trans swap.. 350/th350 auto... got everything back together.. car starts right up.. idles fine.. rev the throttle sounds good.. short drive when cold and it drives fine... after it gets hot .when I shift the car into drive the engine revs to over 3000 rpm without touching the throttle.... the brakes almost wont hold it back and I have to shift it back to park.. and shut it down.. I can start it back up and it idles perfect... but as soon as I shift it.. revs bad..

switched carb with known working one.. no change...
plugged all vac lines in and out of carb.... no change..
nothing it hitting the throttle..
12v to electric choke.. tried moving it and disconnecting it...

anyone?? thanks....

jman1

I took a video of the linkage moving all by it self as I shifted from park to drive... I zip tied the linkage so it couldn't move and no rev... what could cause the linkage to move without pressing the gas....???

diehrd

POST video ..

diehrd

You may have a bad mount causing the motor to shift which makes the throttle move .

jman1

good call!!

OMF

Weak throttle return springs Two springs are a must....

maxmachz

Kickdown cable.....disconnect it from the carb linkage.....

bluedawg

I've not heard of this before, try the double springs as suggested if that don't work or even if it fixes it, post a youtube link, I'd like to see it.