The Stovebolt Site Forums The Shop Area Engine Shop Accelerator Pedal Sticking

1952-53 216 with engine #GM26 3835794.
Accelerator is sticking on me when I push the clutch in to switch gears. Going to start by lubing the throttle linkage. Any other thoughts on this?

Can you tell what's rubbing on what?

Is the return spring in place?

I don’t see anything rubbing. Had my wife push the pedal down.

I'm trying to visualize how the clutch and throttle could contact each other. I'll have to look at my truck tomorrow.

Thanks

Well, I looked at my truck and I don't see any way that the clutch and throttle could be related in such a way as stepping on the clutch could affect the throttle linkage.

I think it must be a coincidence. Maybe when you're backing off on the gas pedal to work the clutch, the rod is binding in the firewall or something similar.

As you said, lubricate any connections and look at where the rod goes through the firewall. What's the story on your throttle return springs? Are they connected properly?

I will check throttle return springs as well. I have truck for 3 years and this is the first time it’s happened.

Did this start All of the sudden?
What linkage do you have from pedal to carburetor?
I have seem some pretty cobbled up rods (linkage) and some had the smallest return spring.

Try pushing the pedal side to side instead of straight down.

I was helping some people last fall that when the wife would push the clutch, she would turn slightly in the seat and end up pushing sideways on the accelerator pedal and it mulched the bushing in it.

Maybe your bushings/linkages are slightly worn and it only binds when you don't push straight down.

Check the motor mounts for looseness. It might be possible that pushing on the clutch pedal is causing the linkage to bind a little by shifting the engine/trans position slightly.
jerry

Thanks for the recommendations guys. I’ll work on it some more this evening and check.

See pictures here of the linkage and pedal spring.

I assume you are letting off on the gas when pushing in the clutch? Is the spring rubbing against a arm of the linkage? Might consider relocating the bottom end of the accelerator spring at the oil pan slightly towards the rear?

Yes, when I let off gas and push clutch in, gas pedal sticks.

It looks as though there might be some tension on your throttle cable below the clamp which would require a heavier return spring to bring it back to idle. I would first disconnect the cable and try it to see if it helps but then reinstall it with the end of the cable at the clamp and only the inner wire extending down to the rod in better alignment. If the wire isn't long enough to reach this way you can cut the cable shorter by pulling the wire back inside of the cable and then cut the cable which will allow for more wire to be exposed

It doesn’t appear in your picture that the throttle cable is attached correctly. The cable takes the place of a cotter pin and extends thru the rod with a cable stop approximate 1/16” below the accelerator rod.

Here is a page from the Assembly Manual showing the setup.

Lots of good suggestions here. Having been through a sticky throttle journey of my own and having (finally, hopefully) resolved it.

The hand throttle can create issues. Phak1 makes a good suggestion. Make sure the hole that cable runs through in the vertical rod doesn’t have grooves. Also, too long of a “tag end” on that cable can grab the top of the manifold at times.

Jerry’s idea about the motor mounts is definitely worth exploring.

But if both of those things check out᠁.

* it won’t be any fun, but I’d dissamble everything from the pedal to the carb and have a look.

* with all the moving parts, even just a little bit of grooving and/or egg shaped holes᠁.all that friction adds up.

* it would be an easy enough thing to move the spring connector one position rearward. It’s just underneath an oil pan bolt. I don’t think that’s your problem, but it probably shouldn’t be rubbing.

I can take some pics of the “rebuild” I did to my linkage later on. It’s way, way smoother now.

@PHAK - my throttle cable is disconnected. I don't use it on my engine. Just the choke. Should I be?

Well
Not until you figure out what’s causing your throttle to stick. I like my throttle. I use it after starting, when I’m warming up the truck so I don’t have to continue using the choke. The choke dumps raw gas into the cylinders washing the oil off the walls and some seeps into the crankcase past the rings, contaminating the oil. The sooner you can get the choke off the better it is for your engine.

Ok I see. Yes ever since I switched to electronic guages I haven’t had a throttle cable. Perhaps I should considersider going back to mechanical guages? Hmmm idk

Is there a simple way to reconnect the throttle even tho my guages are electronic now?

It doesn't matter what kind of gauges you have.

Just buy a throttle cable from one of the restoration places and install it. Does your carburetor still have the bracket that holds the throttle cable and choke cable?

Thanks Otto.
Not sure if I still have the bracket or not. If not, I’m sure I can find one.

Though a good thing to have I wouldn’t go down the throttle cable wormhole until the sticking pedal is completely resolved, completely resolved᠁it will just complicate diagnosis.
If you have ruled out the big items identified by others ( motor mounts etc) then dig into the subtleties.
If you look at the Phak provided diagram, note that the brackets align for a perfectly straight cable pull, this is important for long term safe operation. Side torque on these cable pull is not good in the long term, side load wears parts in a way not intended᠁ if the cable is not at straight pull adjust to get it so.
Also the spring needs tension even in resting position, and shouldn’t be rubbing on anything᠁adjust or change acccordingly.
Disconnect all cables and see that the carb itself is snapping closed just with the spring᠁.consistently, then connect 1 piece at a time and check that, then keep going᠁.
Be safe, can’t drive her with a sticking throttle.

Chuck

There is two things I see in your photos. I copied your pictures for illustration. In the first picture, under the magnifying glass it appears that the horizontal accelerator rod is contacting the bolt sticking out from what appears too be a freeze out plug. In the second picture, I see that you already have the necessary bracket to hook up the throttle. You would only need the cable stop available at any lawnmower or bicycle shop.

But as Chuck has said, don’t mess with it until you sticking problem is resolved.

I’ve included a picture of my throttle setup as reference.

Here's a cable stop. I got it from a local bike shop. It has an Allen head screw to lock it in place.

Dorman sells a pack of two that can be obtained off the shelf at chain auto parts stores.

Thanks everyone! I believe I was able to get the pedal from sticking. Lubricated the linkage and it seems to be much smoother! I’ll let you know if it remains.

Going to get a cable stop today.

I took another look at the throttle rod and it is definitely coming in contact with that bolt as mentioned. What’s my recourse here?

Grind part of the threads off for clearance, or replace that freeze plug with a regular style one.

Seems to me, if you remove the cotter pin at the bell crank, you should be able to move that part of the throttle linkage sufficiently out of the way to grind that bolt back giving you the clearance you need.

Great feedback guys! I did take it out for a drive tonight and the gas pedal was very smooth like it used to be. At this point all I’ve done is lubricated the linkage. I will probably still grind that bolt down though, but I worry about if I ever have to remove it.

DSJ41,

If you grind the last couple of threads off that bolt, just use a small needle style (jewelers) file to dress the rough thread edges. If you give them a slight bevel along the outer thread edge, they won't be a problem if you need to remove the plug and removing the sharp edges may keep more skin on the backs of some knuckles the next time you happen to reach down into that area for some reason.

Dan

Glad to hear. I would have a helper push the accelerator down all the way and double check to make sure the linkage isn’t contacting the bolt throughout the entire movement. It would be a really scary ride if the carb was stuck wide open.

DSJ41 Check your engine mounts,some of them are washed away by years of oil with no service (changing them). Oil will finally melt away the rubber so much the whole engine will shift when you clutch it.

Thank you all!

Otto,

What is the red arrow pointing to in your picture? Also, I included a couple pictures of my set up. The issue I’m having now is. I can’t pull the throttle knob back.

Not sure what If what I’m seeing is correct, but if the cable housing is close to the cable pinch bolt it will limit cable travel, there needs to be a length of exposed cable equal to or more than desired travel, the cable housing does/should not move when pulling the cable᠁..
Be sure all cables pull dead on straight᠁᠁adjust brackets as necessary to achieve straight pull᠁..if the cables angle you get premature wear on the parts, cable acts like a file᠁..I see wear/ovaling in some of these photos᠁..not sure if that is on yours or someone else’s reference photo᠁.᠁

Chuck

I agree with Chuck. You need to shorten the cable sheath. It should be just below the clamp. Use a magic marker and mark the sheath just below the clamp. Straighten out the end of the wire or cut the excess so there is no kink in the wire, pull it back into the cable so you don’t cut it then and cut the outer sheath at the mark you just made. Reassemble and readjust so when the throttle is pushed in all the way, the stop is 1/16” below the accelerator rod.

I agree that the end of the throttle cable housing is way too close to the linkage (cable stop). As far as I'm concerned it should not be protruding more than a 1/4” below the cable housing clamp that is attached to the carb. Here’s a pic of my setup and yes I could shorten my cable housing just a tad, but I have lots of travel, the way it's set.

Thanks for the feedback everyone. I shortened up the sleeve and the wire and I seem to be in a good position now. I noticed that the lower spring is rubbing in the throttle rod. Can y’all send me pictures of your lower spring hookup?