Throttle return spring - sticky gas pedal

[Vsantoro]

The 62 had a sticky gas pedal since I got it.
I bought a new return spring which helped but didn’t fix it completely.
Took apart the full linkage , cleaned and greased everything. That helped but it was still sticky.

Ended up making this.
It’s just a 3$ screen door spring from tractor supply, cut and bent it. Fixed the problem 100%.

So if your experiencing the same thing this works great.

[Lane66Monza]

Sometimes the engine linkage is not the cause of the sticky accelerator and failure to return to idle. My 66 More Door had a similar issue. Two items were causing the issue.

1. Accelerator pedal was dirty and rusty at its swivel bracket. I took it out, disassembled, and bead blasted it. Rust Fix was used on pedal shaft and then light coat of black paint except taped off bushing areas. New bushings were then installed and it was reassembled. It was reinstalled and tested. It seemed better, but still intermittently hanging up at 1100 rpm.

Further inspection to determine the cause was done.

2. I found that the bearings used in the modified engine accelerator system were sticking. I used alcohol to clean the bearings and this resolved the issue completely.

No accelerator problems now in over a year (1500 miles) of driving car.

[jimbrandberg]

I would also say that the swivel at the bottom of the pedal is often the culprit.
It's sort of a pain to jack up the car, remove the tunnel cover and pull back the carpet inside in order to remove the assembly to the bench. I trace the angle of the rod to the pedal so it can be reassembled on the splines correctly. It takes a fair amount of wire brushing and cleaning to get it operating freely again sometimes. I don't know that I've ever replaced the plastic bushings. I just use regular grease, maybe WD-40 as more of a cleaner.
Holding the gas pedal down against a big spring is fatiguing and all that pressure can't be good for the accelerator system.
Of course there are many other places that can be binding but that's often the big one. You can isolate different parts of the system to check them out.

[RexJohnson]

The rod coming up from the trans looks like it is bent towards the outside of the car. I thought that on the early cars the rod attached from the center of the car so that the end of the swivel pointed towards the outside keeping the spring in a straight line back to the air cleaner base? This could be some of the problem.

[caraholic4life]

A good way to determine where the "Sticky" is at would be to start by disconnecting the rod that comes into the engine compartment from the cross shaft linkage. Once that is done, see if the "Sticky" is still present or not.

IF the "Sticky" went away, hook the linkage rod back up to the cross bar then disconnect the linkage at the transmission/differential area where the rod coming from the front of the car connects.
Disconnect the rod that comes from the front of the car and see if the "Sticky" returns or if things are still working smoothly.
Removing the Left rear wheel might make this part easier.
Remember to use good Jack Stands....Do not get under the car without proper support.

IF you determine the "Sticky" is somewhere else, it is likely in at the accelerator pedal as previously mentioned and the carpet will need to be dealt with in order to address the pedal and linkage at that point.

For what it is worth, using a heavier return spring at the carburetor's may be an acceptable short term solution but it could potentially create other issues in the long run.

[jimbrandberg]

It can take some time but be quite satisfying to sort out the accelerator linkage. A lot of times it just takes some bending and tweaking. Sometimes the wrong parts have found their way in there by folks thinking "they're all the same".
There's some good instructions in the '61 Service Manual for a step by step adjustment of the system, starting at the crossover shaft and ending at the pedal angle. It's especially important with a Powerglide because the accelerator linkage swivel at the transmission is also the throttle valve (TV) which affects when the transmission shifts.
Someone mentioned the shape of the rod coming into the engine compartment. With the boot out of the way you can watch the action of that to make sure it isn't hitting the shroud. It can take several trips to the vise to get it bent just right. Besides Early and Late, there's more than a few styles of how these are bent and more than a few styles of crossover shaft.
If you go through the adjustment procedure I'm sure your source of binding will become apparent. There may be more than one. Just narrowing it down from fore or aft of the swivel at the transmission will help. I would approach it with the mindset that it might take all day with the car jacked up.
The threaded adjustment of the rod going forward from the swivel is sometimes rusted stuck and best addressed at the bench with oil and heat and patience.
A nice return to idle, carburetors that actually attain wide open throttle and a light feel for your foot on the throttle are a joy. My '60 80 HP PG daily driver is a nice little overachiever because I can tailor my shift points with throttle position.
The hardest part of fixing the pedal swivel is making the decision to go after it.

[Lane66Monza]

Donna was driving our 66 More Door home from Corvair Springfest in Helen GA. Rick had his Vair More Door and I had the truck with RV trailer. About 30 miles from home in Statesboro, she called me saying she had no control of the engine. Pedal would stay close to the floor. I asked her if she could drive it as is for about 2 miles to the gas station that was coming up, where we could fix the issue and get gas. It was time for a refill at that time. She said she could do it. I called Rick and explained problem and where we would be stopping. He was about 15 minutes behind us at that point. Donna drove it by lifting up the pedal with her foot and using neutral when at idle, until she got to the gas station where I was parked. I went to see what the issue was with the car. She was halfway into a gas pump row now. I opened the hood and accelerator return spring was off. I explained we had to move car up to a pump to clear drive area. I informed her, I would operate engine and she had brakes and steering. She started up the engine. I asked he to hold brake while I kept the engine at ide. With my directions she put it in drive and released the brakes. I manipulated the engine linkage to move car slowly to pump. he braked and selected neutral at my direction. Then she set parking brake and shut down engine

The accelerator return spring had come off at the shroud spring attach point. I had a spare spring in in parts bag, so Rick and I worked on a more secure attachment. We bent and wrapped the spring into the shroud spring attach point. That fixed the first issue with it coming off, but Rick wanted to improve the engine linkage connection. The spring was being stressed with its end in the linkage hole, a prelude to it failing with enough cycless We all met at Tractor Suppy to get a cotter pin to fit the engine linkage spring attach point. At the engine linkage, Rick inserted a cotter pin and bent cotter pin tails to a butterfly configuration. Then he slipped the spring into the cotter pin loop and bend the tail to prevent it from coming off. This gave a smoother spring transition when operated. A small tweak had to be done to the spring length to make up for the using a new spring and mods done for the installation. It has been working fine now for 3 years with many long distance trips. Pedal pressure is good with pedal coming back crisply without high spring force to overcome.

The old and new springs were Clark's C501 springs. Good springs, if installed properly.

[Project65]

Hey Vsantoro,

Just went through my entire linkage today. As I started into this a week or so back, my thoughts were this…. This is my accelerator…I’m not going to go cheap here…. I don’t want some sticky throttle that could surface as a serious driving hazard. I ordered from Clark’s the complete bushing and washer kit and went through the entire linkage on my car that I’m restoring. The kit costs is much less than an accident. We have +60 year old cars with worn out parts. I’d advise rebuilding the entire linkage.

[Lane66Monza]

Here is an illustration of the LM pedal assembly and things to do (and not do), when reworking it. EM pedal is similiar.

LM accelerator pedal rework.jpg (46.2 KiB) Viewed 1082 times

[RexJohnson]

Make sure if you take the pedal off of the assy that you put it back on at the same angle. I believe that the assy manual shows the correct angle that it needs to be. If you can't get the throttle to do what it needs to (pedal on the floor and can't get full throttle) the pedal could be on at the wrong angle. The pedal splines to the shaft with no keyway to put it back to the correct spline.

[Wittsend]

I count 24 pivot points in the Corvair throttle system (did I miss anything?). And that includes combining the cross shaft pivots (2=1) and throttle shaft pivots (2=1 ea.). Otherwise the number would be higher..., and if you want to count your ankle too... . Cumulatively they all add up to some form of resistance.
1. Pedal pivot at floor.
2. Rod pivot connection, beginning of tunnel.
3, 4, 5. Rod pivot to additional rod, end of tunnel.
6, 7, 8. Rod pivot at transmission.
9. Rod pivot at cross shaft connection.
10. (counting common for both) Cross shaft pivots.
11, 12. Passenger side cross shaft pivot to throttle blade pivot.
13. (counting common for both) Carb throttle shaft.
14, 15. External accelerator pump rod pivots.
16. Accelerator shaft pivot.
17. Accelerator pump pivot.
18, 19. Driver side cross shaft pivot to throttle blade pivot.
20. (counting common for both) Carb throttle shaft.
21, 22. External accelerator pump rod pivots.
23. Accelerator shaft pivot.
24. Accelerator pump pivot.

[Frank DuVal]

witsend6, 7, 8. Rod pivot at transmission (Auto).

Powerglide or manual transmission, early or late, there is a pivot there.


Internal Server Error?

[Wittsend]

Thanks Frank. I deleted the "(Auto)" reference to reflect your information. I thought it might be the same auto or manual but since I only own an auto it seemed wise to stipulate what I used as a reference.

At my house an "Internal Server Error" means my wife didn't make something I like for dinner.