Throttle Lever Sneaks Down.....

C

CatMan1

Senior Member
On my '28 Sport Coupe the throttle lever keeps dropping and thus raising the idle speed. Not ideal for shifting. What causes this? Can it be adjusted/fixed in any way?
 
Pull up on the lever. There is a spring at the bottom that should provide a fairly heavy resistance to the pull. If not then the spring may be broken or otherwise need replacement.

Some sectors are worn so that the notches do not offer any resistance to the hand throttle lever. People have filed the notches to restore them. I have used a rubber or plastic hose slipped over the lever to offer more resistance.

It could also be that the return spring on the foot throttle is week or broken. The vendors sell two different types of these springs for the different styles used in different years. There are instructions on the Snyders site for how to change the springs and which ones to use. However the return spring for the foot throttle would not be in the equation when you have your foot pressing on the throttle, only during idle.
 
I had a car that had a similar issue. It turns out that the rod from the steering column to the throttle linkage was too long, and it wasn't letting the throttle linkage return spring fully close the throttle. You could force the lever, but once you took your hand off it and depressed the gas pedal then the problem returned. I solved the problem by cutting the rod, removing a quarter inch or so, and putting a coupler in it, which shortened the rod. In hindsight I could likely have also loosened the steering housing and rotated it. Others that have had this problem simply bent the rod to shorten the point-to-point distance.
 
The parts sources offer only two different lengths of the control rods for replacement. Originally, there were four or five different lengths so it depends on whether they are new or original parts and which steering column & gear is installed. The springs and the little linkage arms are all the same basic part. I've not yet found a reference that lists the length of all the OEM rods. A person may be able to cut down the longer 1930 & 31 rods to fit the shorter ones. Drilling the pin hole for the arms wouldn't de too bad a job.

I use a Swiss triangle shaped file to deepen the worn notches on the old well worn quadrants. The 7-tooth set ups require a little more work to replace the spark & throttle rods since the column tube is integral with the steering gear.
 
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rotorwrench said:
I use a Swiss triangle shaped file to deepen the worn notches on the old well worn quadrants.
Click to expand...
I've done two recently. One was worn flat so I couldn't even see where the notches were supposed to be. I ended up sourcing a used throttle lever plate and installing it, it works great. The second one I used a triangular pattern-makers file (like your Swiss file) and restored the notches. I don't have that column back together yet so I don't know how successful I have been.
 
JayJay said:
I had a car that had a similar issue. It turns out that the rod from the steering column to the throttle linkage was too long, and it wasn't letting the throttle linkage return spring fully close the throttle. You could force the lever, but once you took your hand off it and depressed the gas pedal then the problem returned. I solved the problem by cutting the rod, removing a quarter inch or so, and putting a coupler in it, which shortened the rod.
Click to expand...

I cut the rod and made it adjustable. Not that I need to adjust it often but when I switched from a Zenith to a Marvel I found I need a shorter rod.


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