[tdavidl]

i did a search of these forums & couldn't find a thread about this issue:

as i'm depressing the foot pedal, about an inch info it, there's a sticky point, something is hanging up...i can push thru it, its annoying though...

i thought maybe the pedal on the inside of the car as getting a little rusty so i applied some silicone...the "hitch" is still there...so it must be in the cable or the carb linkage...

carb was recently fixed to correct a "bog" when just starting out (no bog ay all if i mashed the pedal)....bog is gone & this just recently developed...

how do i go about tracking down where the hitch is?

71 400, orginal 4 bbl carb...

[steve25]

It may be the carb throttle plates hanging up in the bore.

If you loosen all four of the carb hold down bolts does the issue change?

[tdavidl]

Originally Posted by steve25

It may be the carb throttle plates hanging up in the bore.

If you loosen all four of the carb hold down bolts does the issue change?

will have to check...i'll put that on the list of items to check...thx

[ta man]

Check carb gasket interference also.

[Half-Inch Stud]

Throttle Cable is capable of a hsving a broken steel wire strand that digs into the sheath.

[Scott65]

Pedal bushings can make one sticky.

[Joe's Garage]

Try working the throttle - with the engine OFF - using the short length of cable that is exposed right where it attaches to the carburetor.

It's sometimes easier to do this with the throttle springs removed, but REMEMBER to reattach the springs before you close the hood.

You may find that the 'stiffness' is the return spring on the secondary throttle shaft offering more resistance when you push into the secondaries.

If it is a cable problem, you will be able to feel the binding in the cable. In that case, disconnect the cable at the carb attachment and check the carb alone for smooth operation.

Good luck!

[punkin]

Any possible alignment issues where the cable may be pulling at the throttle shaft at an angle?

Perhaps pull the cable off the carb linkage and attached a return spring to the cable end and exersize it to see if the problem remains with the cable or foot pedal assembly.

[tdavidl]

Originally Posted by punkin

Any possible alignment issues where the cable may be pulling at the throttle shaft at an angle?

Perhaps pull the cable off the carb linkage and attached a return spring to the cable end and exersize it to see if the problem remains with the cable or foot pedal assembly.

not that's noticeable...thx for the tip, will add that to my list of ways to narrow in on the problem

[tdavidl]

Originally Posted by Joe's Garage

Try working the throttle - with the engine OFF - using the short length of cable that is exposed right where it attaches to the carburetor.
yep, tried that several times and still couldn't identify where the "hitch" was...carb, pedal or cable...

It's sometimes easier to do this with the throttle springs removed, but REMEMBER to reattach the springs before you close the hood.

You may find that the 'stiffness' is the return spring on the secondary throttle shaft offering more resistance when you push into the secondaries.

If it is a cable problem, you will be able to feel the binding in the cable. In that case, disconnect the cable at the carb attachment and check the carb alone for smooth operation.
i'll try this... i was playing with the actual linkage when i was trying at the cable connection to the card, NOT specifically holding the cable...thx

Good luck!

see above

[78w72]

Originally Posted by Joe's Garage

Try working the throttle - with the engine OFF - using the short length of cable that is exposed right where it attaches to the carburetor.

It's sometimes easier to do this with the throttle springs removed, but REMEMBER to reattach the springs before you close the hood.

You may find that the 'stiffness' is the return spring on the secondary throttle shaft offering more resistance when you push into the secondaries.

If it is a cable problem, you will be able to feel the binding in the cable. In that case, disconnect the cable at the carb attachment and check the carb alone for smooth operation.

Good luck!

this is common on q-jets. all my cars with late 70's q-jets do this, i can feel it in the pedal when the secondaries just start to open. no cable or pedal bushing binding, it just takes a little more force to open the secondaries.

not saying that is your issue, its a good idea to check all the things mentioned above, but if there is no binding in the cable or pedal bushing issues, it could just be the resistance of the secondaries youre feeling.

[tdavidl]

Originally Posted by 78w72

this is common on q-jets. all my cars with late 70's q-jets do this, i can feel it in the pedal when the secondaries just start to open. no cable or pedal bushing binding, it just takes a little more force to open the secondaries.

not saying that is your issue, its a good idea to check all the things mentioned above, but if there is no binding in the cable or pedal bushing issues, it could just be the resistance of the secondaries youre feeling.

thx...just started after the recent rebuild so you may be right

[tdavidl]

Originally Posted by Scott65

Pedal bushings can make one sticky.

that was my first thought which is why i figured the first easy step would be to spray some silicone under the pedal...didn't resolve the issue :-(

[Scott65]

Spraying them won't do any good if they're cracked or broken. They're plastic and can crack. If you eliminate everything carb and cable, pull the pedal assembly and take them out and have a look.

[400 Lemans]

Could be the secondary lockout if its doing it while still cold and the choke isn't fully open yet. That will make the throttle harder to push when trying to get into the secondary throttle blades.

[Joe's Garage]

Originally Posted by 400 Lemans

Could be the secondary lockout if its doing it while still cold and the choke isn't fully open yet. That will make the throttle harder to push when trying to get into the secondary throttle blades.

To test for this being the problem, hold the choke blade fully OPEN and check the throttle action under the hood.

The lockout is on the passenger's side and is not difficult to disable. The secondary throttle blade lockout, AND the secondary flapper lockouts on the earlier carbs are removed or disabled as standard procedure whenever we work on a quadrajetjet.

Here's a video:
https://www.youtube.com/watch?v=_mwX06-3LV8

Good luck!

[tdavidl]

Originally Posted by Joe's Garage

To test for this being the problem, hold the choke blade fully OPEN and check the throttle action under the hood.

The lockout is on the passenger's side and is not difficult to disable. The secondary throttle blade lockout, AND the secondary flapper lockouts on the earlier carbs are removed or disabled as standard procedure whenever we work on a quadrajetjet.

Here's a video:
https://www.youtube.com/watch?v=_mwX06-3LV8

Good luck!

thx, yea, that's not the issue since its happening all the time, same spot on pedal push all the time

[tdavidl]

Originally Posted by 400 Lemans

Could be the secondary lockout if its doing it while still cold and the choke isn't fully open yet. That will make the throttle harder to push when trying to get into the secondary throttle blades.

happens all the time, any temp...same spot in pedal push....maybe an inch into the push of the pedal

[tdavidl]

Originally Posted by Scott65

Spraying them won't do any good if they're cracked or broken. They're plastic and can crack. If you eliminate everything carb and cable, pull the pedal assembly and take them out and have a look.

thx, will do

[JLMounce]

I recently had a similar thing happen, but it was hanging on throttle close. Verified at the TBI, no issue, but at the pedal there was a bind. Turned out to be the factory cable was fraying inside it's sheath near the peddle assembly.

If it's the original cable, it would be worth removing and inspecting the movement of the cable within the sheathing to verify that's not the cause.

I replaced with a Lokar cut to fit cable which is very nice.