Throttle/Carb sticking 2bbl 318 LA 70 Coronet

[FranksCoronet]

okay guys so about a week ago I was driving and my gas pedal stuck to the floor and took me for a ride. I made a thread about it here
http://www.forbbodiesonly.com/moparforum/threads/wild-ride-in-the-70-coronet.140029/#post-910798851

Now I got the car back from the mechanic and was driving it and I noticed that the car would slowly push harder and harder at redlight until I couldn't stop it. I got it home and threw it in neutral and it revved super high so I shut it down. When I got home the screw I marked in yellow wasn't touching the one I marked in green at all. Mechanic got it again and fixed the cable or whatever or adjusted it, long story short I finally get to drive it again and it starts to do it again ever so slightly. When I got home the marked yellow screw wasn't touching the marked green one. I had to get out and move it back. Everything is there but it seems as though it just won't go back to how it should when there's no power on here pedal. I included this picture and marked stuff in green and yellow because I'm not too savvy with exact part names cause I'm still in high school and it's my first car lol. Any help would be appreciated. I think it may be the return spring? But I never had trouble with it before or could it have something to do with the carb?

 

[FranksCoronet]

I meant "when there's no power on the pedal"

 

[drobertson]

I'd start by spraying some carb cleaner all over the linkage. That'll help un-stick things. If your idle is too high, check for vacuum leaks. You could use a stiffer throttle return spring, but that'll make the gas pedal harder to push down.

 

[oldbee]

As above , also make sure your choke is opening like it should & fast idle cam is moving like it should.

 

[FranksCoronet]

I'd start by spraying some carb cleaner all over the linkage. That'll help un-stick things. If your idle is too high, check for vacuum leaks. You could use a stiffer throttle return spring, but that'll make the gas pedal harder to push down.

Yea it's just weird cause it was stuck on open throttle before and like half throttle also. Could it being gunked up really cause it to stick that bad?

 

[mopar 3 B]

yep

 

[coloradodave]

Frank,
Gonna need closer up pictures so old, tired eyes can see your linkage up close. I would pull off the air cleaner, disconnect the linkage from the carburetor and open the throttle by hand. Does it "snap" shut when you let it go? It should. If not, hit the throttle shaft and exterior of the carburetor with some Gumout or Berryman's carb cleaner. If the throttle does snap shut, the problem is most likely in the throttle cable (or transmission kick down lever), which could be gunked up or frayed inside it's casing. Again, hold the carburetor end of the cable and have someone work the gas pedal in the car. Does it move smooth and easily? If not, shoot some carb cleaner into the cable casing at the carb end and work the pedal several times to see if it frees-up. If it doesn't, most likely the cable is frayed near one end or something is affecting the movement of the pedal. Both are easy to check.
Good luck and let us know what you find.
Dave

 

[SublimeSixpack]

I'd like to see a better photo image of where your accelerator cable is clamped. Doesn't look right to me in the photo you posted. Looks as though it's clamped right on the housing itself instead of the metal sleeve. If it's clamped on the housing itself that could cause the cable inside to bind.
Also, FWIW there should be a spring attached to your kick down (throttle pressure) rod for proper operation of your transmission.

 

[FranksCoronet]

Frank,
Gonna need closer up pictures so old, tired eyes can see your linkage up close. I would pull off the air cleaner, disconnect the linkage from the carburetor and open the throttle by hand. Does it "snap" shut when you let it go? It should. If not, hit the throttle shaft and exterior of the carburetor with some Gumout or Berryman's carb cleaner. If the throttle does snap shut, the problem is most likely in the throttle cable (or transmission kick down lever), which could be gunked up or frayed inside it's casing. Again, hold the carburetor end of the cable and have someone work the gas pedal in the car. Does it move smooth and easily? If not, shoot some carb cleaner into the cable casing at the carb end and work the pedal several times to see if it frees-up. If it doesn't, most likely the cable is frayed near one end or something is affecting the movement of the pedal. Both are easy to check.
Good luck and let us know what you find.
Dave

Thank you I'll get some better pictures and try that out. Could it be the kick down lever? Before all this started I kinda leaned on it bad so I suspected it. And what do you mean by the casing? Thank you so much for the help

 

[FranksCoronet]

I'd like to see a better photo image of where your accelerator cable is clamped. Doesn't look right to me in the photo you posted. Looks as though it's clamped right on the housing itself instead of the metal sleeve. If it's clamped on the housing itself that could cause the cable inside to bind.
Also, FWIW there should be a spring attached to your kick down (throttle pressure) rod for proper operation of your transmission.

I'll get better pictures tomorrow. And isn't that thinner spring hooked up to the kick down poperly? Thank you

 

[SublimeSixpack]

I'll get better pictures tomorrow. And isn't that thinner spring hooked up to the kick down poperly? Thank you

Pretty sure it should go the other direction - back to the pivot (if it's the same set up as what my '68 Coronet 318 car came with).

 

[FranksCoronet]

Pretty sure it should go the other direction - back to the pivot (if it's the same set up as what my '68 Coronet 318 car came with). If Photobucket hadn't gotten so stingy I'd post an image to show you what I'm talking about.

Huh. It's been like that since I got the car. Here's an older picture

 

[SublimeSixpack]

Huh. It's been like that since I got the car. Here's an older picture

View attachment 534468

The thing is, the way it's attached now it's acting as an throttle return. That smaller spring is there to pull the rod forward. I'm thinking the spring should go from the throttle stud to the other end of the rod, just above the pivot. I'm not suggesting this has anything to do with your sticking throttle, but it's probably affecting how your trans. upshifts.
Make sense?

 

[khryslerkid]

You can disconnect the throttle cable from the carb and feel how much resistance is in the cable. Push and pull it, you'll feel the gas pedal moving. There is hardly any effort to do this. If it's binding then you need to correct it.

If the cable seems ok, leave it disconnected and study your carb linkage operation. Sometimes you have to see what makes things work to find your problem. Good luck.

 

[threewood]

I agree with KK. Pull the cotter pin off the carb throttle stud, remove throttle cable from carb. Check carb operation without the cable attached. Also check cable operation by itself.

 

[FranksCoronet]

The thing is, the way it's attached now it's acting as an throttle return. That smaller spring is there to pull the rod forward. I'm thinking the spring should go from the throttle stud to the other end of the rod, just above the pivot. I'm not suggesting this has anything to do with your sticking throttle, but it's probably affecting how your trans. upshifts.
Make sense?

Makes a little sense. I'm still kinda a newbie. Think I could see a picture of yours if you get a chance?

 

[SublimeSixpack]

Makes a little sense. I'm still kinda a newbie. Think I could see a picture of yours if you get a chance?[/QUOTE

Here's an image from the Coronet when I first bought it. Hopefully it'll post.

 

[SublimeSixpack]

Here's a little different set up on the 360 that's in there now but you'll get the idea.
But again this is just related to the kick down (throttle control) rod. Not the main issue you're having.

 

[oldbee]

Head knock!! I was so fixated on the op problem I never even looked at linkage pic. Some sharp eyes caught that.

 

[threewood]

Huh. It's been like that since I got the car. Here's an older picture

View attachment 534468

Ok, first get the camera closer to the linkage. My binoculars can't zoom in that far lol.