Sticking throttle or something

[Godwin]

Recently I've been experiencing occasional high idle on a 2F with stock carb and linkage. It would be noticeable after having been driving then with the clutch in as the idle would be sticking at 1500-2000 rpm. Lifting under the throttle pedal or tapping it would drop the idle to normal. Something has been sticking. I checked for an obstruction along the linkage and but found nothing interfering with the linkage. I then checked the gas pedal and found some play in it. A pivot bolt with nylon bushings connects to pedal to the base and I noted that the bushings seemed to be worn. I've attributed this to the sticky, high idle condition. I've swapped out this old with a lower mileage, less older pedal with tighter bushings and expect this to have cured the issue. Haven't driven the 60 yet to check it.

Went to my local Toyota to purchase replacement nylon bushings but they're not available separately.

A photo of the mounting bracket and pivot bolt.

 

[CaptClose]

I've had this exact condition on and off. It's a bit annoying to keep jamming my fit under the gas pedal to alleviate the throttle. I'll be watching this thread with interest. Good luck!

 

[roscoFJ73]

Ive had this problem, it could be the spring inside the bracket. When they get old they don't return the pedal to its proper position.
It may feel ok when you twist it with your fingers but when you compare it with new one there is a definite difference.
Spring is available to the best of my knowledge. part number 90508-29017

 

[Godwin]

There is no spring inside the bracket. The return spring attaches to the pedal arm and firewall.

 

[roscoFJ73]

I knew there was spring somewhere.

 

[Godwin]

Short drive this morning and the throttle operated smoothly. More testing to come.

FJ62 pedals have a spring-loaded mounting base. This one pictured is actually a hybrid 60/62 pedal when I installed a 3FE into the FJ60.

 

[Jesper]

Same thing happened to me on my trip home from FL to MT. I've never experienced this until I got into freezing temps. I attributed it (guessed) to road spray and moisture coating the linkage and freezing over while the pedal and linkage are held in the same position for extended periods of time.
First time it happened it really freaked me out. I had been cruising for about 2 or 3 hours at 55+ steady and hit an exit ramp. Instinctively came off the gas and put the stick in neutral. RPM's took off, sounded like the truck was trying to run away on me, and it took about 2 -3 seconds of "WTF is going on???" before I jabbed the gas pedal and brought it back to normal...noticed nothing out of the ordinary when I visually inspected everything. Hasn't really happened on any short grocery-getter trips, so..... I dunno.

 

[Godwin]

As the 60s age this may be an obscure wear item to watch. The pedal assembly I removed has ca. 380k miles on it.

 

[TexasBlue]

Top pic shows dirt, clean it and 3-in-one oil it. See how that works..my 2cents Ive done that on other vehicles with sticky linkage and it helped.

 

[roscoFJ73]

Short drive this morning and the throttle operated smoothly. More testing to come.

FJ62 pedals have a spring-loaded mounting base. This one pictured is actually a hybrid 60/62 pedal when I installed a 3FE into the FJ60.

View attachment 1400621

That's a spring in bracket

 

[Godwin]

Top pic shows dirt, clean it and 3-in-one oil it. See how that works..my 2cents Ive done that on other vehicles with sticky linkage and it helped.

The dirt is superficial and not the source of the problem. I pulled the pedal assembly apart and the bushings and pivot bolt were clean plus the pedal moves freely but with slop. I think there was enough wear on the bushings to allow some occasional minor misalignment that would cause the linkage to stick.

My 60 gets used and any lubricant in the footing area would be a bad idea. I can only see oil holding more dirt or grit. Dry graphite may help but I still think that the worn bushings are the problem and not an increase in friction.

 

[TexasBlue]

How you descirbe the issue, graphite is good or dry bike chain lube could be alternative to oil

 

[timexlost]

Going to bump this up instead of starting a new thread. Been having this issue for a while, it’s getting annoying. Carb is a city racer, linkage is all nice and clean. I can’t find slop anywhere. Some days, it’s totally fine, others it sticks. Doesn’t matter the temperature or the length of the drive.

 

[DFXR]

Going to bump this up instead of starting a new thread. Been having this issue for a while, it’s getting annoying. Carb is a city racer, linkage is all nice and clean. I can’t find slop anywhere. Some days, it’s totally fine, others it sticks. Doesn’t matter the temperature or the length of the drive.

Not sure if this is your issue, but it was mine: the spring hanger for the throttle linkage, at the base of the carb, can get bent very easily if you're taking the carb off and on, and very especially if the carb has been shipped.

If the hanger is bent at all it can cause the throttle to hang up, either a little or a lot depending on the bend.

Here's a couple extreme examples (courtesy of FedEx shipping) to get the visual. It doesn't have to be this obvious to cause issues. Make sure yours is plumb and level.

 

[CardinalFJ60]

Had the same issue. Was a gummed up ball joint in the linkage under the hood.

 

[timexlost]

Not sure if this is your issue, but it was mine: the spring hanger for the throttle linkage, at the base of the carb, can get bent very easily if you're taking the carb off and on, and very especially if the carb has been shipped.

If the hanger is bent at all it can cause the throttle to hang up, either a little or a lot depending on the bend.

Here's a couple extreme examples (courtesy of FedEx shipping) to get the visual. It doesn't have to be this obvious to cause issues. Make sure yours is plumb and level.

View attachment 3706299View attachment 3706300

Should you ever find yourself in RI or MA please let me buy you a beer.

 

[DFXR]

Cool, I hope this solves it.

Mine was probably bent as much as yours when I bought the truck in 2010. So I dealt with sticking on and off for years before figuring it out. I had never seen it not bent.

After the last go-around, I had to do this (thanks @ChopperBob):

 

[Godwin]

Had some sticking throttle issues this afternoon. First noticed that there was a point with the pedal where there was mild sticking. At first thought my shoe was snagging on the tranny hump, but eliminated that as a cause. The sticking was intermittent but grew worse. At times while shifting the engine would race to 4-4500 rpm before I could bump the pedal, which usually would release whatever was causing the throttle to stick. It became worse to the point that I had a few, or more, instances where the throttle was stuck wide open, but I was on a highway and in 5th gear. Couple of times I had to reach down with my hand and move the pedal for release.

I think I isolated the issue, will find out tomorrow.

This long PCV hose was riding on the shaft and I think from that it was causing the throttle to stick. You can see a spot on the throttle rod where the hose had been lying. It's now zip tied away from the rod.

 

[Godwin]

Had some sticking throttle issues this afternoon. First noticed that there was a point with the pedal where there was mild sticking. At first thought my shoe was snagging on the tranny hump, but eliminated that as a cause. The sticking was intermittent but grew worse. At times while shifting the engine would race to 4-4500 rpm before I could bump the pedal, which usually would release whatever was causing the throttle to stick. It became worse to the point that I had a few, or more, instances where the throttle was stuck wide open, but I was on a highway and in 5th gear. Couple of times I had to reach down with my hand and move the pedal for release.

I think I isolated the issue, will find out tomorrow.

This long PCV hose was riding on the shaft and I think from that it was causing the throttle to stick. You can see a spot on the throttle rod where the hose had been lying. It's now zip tied away from the rod.

View attachment 3707360
View attachment 3707362

View attachment 3707361

Last night's diagnosis was wrong. Dark was coming on, the engine was hot, and I was tired so I focused on the first thing I saw. This morning the 2F was running as if 2 cylinders were misfiring and it would not idle. I drove it maybe 1/2 mile then returned to where I'm staying; I'm 150 miles from home.

In the daylight and with an engine that won't deliver 2nd degree burns I had a closer look at the carb linkage, etc. First issue were two massive cracks in the PCV hose. It's hold and brittle and will be replaced. A couple of wraps of Gorilla tape took care of the vacuum leaks.

I then looked closer at the carb linkage. I was planning on dissembling the rods with ball ends to look for rough spots. Didn't get that far. I operated the mechanism and noted that there was an interference issue with a lateral rod and the bracket under the carb. The triangular piece has a 90 degree bend from vertical to horizontal and a spring is attached on the end toward the firewall. Somehow this triangular piece has become bent upward (constant tension from the spring?) and the lateral carb linkage rod was snagging on the edge of the bracket. I bent the bracket downward until there was no contact issue.

This linkage sticking issue was more serious than I had considered last night.

 

[yotadude520]

Last night's diagnosis was wrong. Dark was coming on, the engine was hot, and I was tired so I focused on the first thing I saw. This morning the 2F was running as if 2 cylinders were misfiring and it would not idle. I drove it maybe 1/2 mile then returned to where I'm staying; I'm 150 miles from home.

In the daylight and with an engine that won't deliver 2nd degree burns I had a closer look at the carb linkage, etc. First issue were two massive cracks in the PCV hose. It's hold and brittle and will be replaced. A couple of wraps of Gorilla tape took care of the vacuum leaks.

I then looked closer at the carb linkage. I was planning on dissembling the rods with ball ends to look for rough spots. Didn't get that far. I operated the mechanism and noted that there was an interference issue with a lateral rod and the bracket under the carb. The triangular piece has a 90 degree bend from vertical to horizontal and a spring is attached on the end toward the firewall. Somehow this triangular piece has become bent upward (constant tension from the spring?) and the lateral carb linkage rod was snagging on the edge of the bracket. I bent the bracket downward until there was no contact issue.

This linkage sticking issue was more serious than I had considered last night.

View attachment 3707939

Shameless plug but I've got a spare throttle linkage assembly if you want to replace it!