Throttle sticking

[joshm121]

Hey guys, figured out recently that a previous owner rigged up my bronco with a spring assisted throttle cable and some airline cable clamps. I hadn't really noticed since my last bronco was a 6 cylinder and had the cable, but looked online and saw that the V8 should have a lever and rod system. Ordered one from Toms and installed. Works except now throttle lever doesn't always seat 100% when i release the pedal, which as I'm sure you can imagine is problematic. I thought it might just need a little lubrication or rod adjustment, but lubed everything and adjusted rods. The mechanism I installed seems to move really well but arm on the carb (holley 2b) still hangs up a little when I hook everything up. Got me to wondering if the carb arm is supposed to have a spring to pull it back (the one barrel on my 6cyl did), but looked up a bunch of pictures on line and don't see one. Any ideas?

 

[gr8scott]

Got me to wondering if the carb arm is supposed to have a spring to pull it back

Yup, throttle return spring.

 

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Sticky throttle

I recently had the same problem with my 302 Carbed throttle linkage using the stock throttle set up. The throttle simply would not seat consistently. Initially, I made certain I had the correct springs; one on the front of the throttle for the kick down and one on the back of the throttle acting as the return. It helped, but it didn't get it done, so I examined the rod that runs through the firewall and attaches to the gas pedal and found that it was rubbing at the base of the firewall opening. I removed the rod, grinded a slightly larger opening with a Dremel drill using a stone pointed drill bit, polished the area with steel wool, burnt my finger while seeing how smooth it was , lubed (lithium grease) the space the rod enters the firewall, took steel wool to the rod to remove worn burrs and it works perfectly.

I'm not sure what throttle linkage you purchased, but check the area at the firewall for rubbing and it may help.

Oh yeah, and don't stick your finger on hot metal to admire your work.

Rob

 

[joshm121]

http://s78.photobucket.com/user/joshm121/media/Screen Shot 2015-09-10 at 7.40.58 PM.png.html

Heres a pic of my carb online. I only see the one spring (green) which is there and seems to be working. Also, I was sure to double check clearance through the firewall and am all good.

 

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Throttle springs

I don't run a Holley carb, but your carb shows a number of holes, which will act as attachment points for springs to get the return you need. Do a google search with your carburetor type and pictures (e.g. Motorcraft 2150 pictures) and you will find a number of pictures and diagrams that, I'm sure, will show the proper spring hookups you need.

Good luck,

Rob

 

[jckkys]

The stock throttle linkage went through several major changes over the years. The early version at least to '70 had bell crank linkage mounted behind the carb and a return spring in front to close the throttle. When the C4 was offered, the bell crank had to be removed to make room for the kick down rod. The larger bell crank on the fire wall was changed to use a single throttle link rod. This linkage use a return spring behind the carb. What year is your Bronco? Your carb pictures show a 4412 Holley with the choke removed. Is that what you have on a 302?

 

[joshm121]

bronco is a 70 but is kind of a hodge podge of parts. That looks like my carb, but not 100% sure. I'll work on getting some pics of what I have and post. Thanks for the help guys.