Re: Runaway Engine

Posted by 55PackardGuy On 2014/10/26 22:18:52

Just a thought:

When you set the head up on the exhaust manifold, it might have leaned up against the side of the carb linkage, If so, this could've bent the linkage around the idle speed set screw. Bending can crank up the engine speed and not show much skew at all in the linkage. If the pressure against the linkage at that point was great enough, it could also have bent the throttle shaft. That condition may only affect it when the throttle plate warms up or the shaft twists a bit while your driving, as you describe. (More on that below.)

If it was me, that's where I'd start looking, right around the area where the linkage meets with the throttle shaft. It might be something pretty simple.

Rather than driving the car, just let it run with the hood up and air cleaner removed, then blip the throttle until it sticks, and have a look. I don't know what your definition of "runaway" is, but if it's too extreme, you can ask a friend to work the accelerator for you. Or, you could just move the linkage yourself and have a friend ready to shut off the key if things get too hairy.

Good luck.