Throttle Sticking weird linkage

[Slewis25]

I am new to the Bronco world, I bought a 69 with a 302 and yesterday I noticed the throttle sticking when I got on it a little. There is a funky linkage that mounts to the manifold, it is in between the linkage that mounts to the firewall and the carb. I would post a pic but I am having trouble adding it to this thread. I have not seen this on other broncos and was curious if anyone is familiar with it. I also noticed that with the pedal on the floor I am only getting a little over half throttle (no good.) I was also looking for any advice on which carb to run, I have heard mixed revies on Holley's Truck Avenger. The Edlebrock on it know is new but very ineffective off road.

Thanks,

Scott

 

[70_Steve]

First, welcome to the site, and to the Bronco community!!

To upload pictures into the thread, pay $12 a year and become a contributor. See this thread (sticky in the Bronco Chat section) for details. http://classicbroncos.com/forums/showthread.php?t=34373 . Or you can have the pics hosted on another server and add a link to the pic.

I haven't seen any other bracket mounted on the manifold. My 70 had a solid link between the linkage on the firewall and the carb. I run a Carter AFB, which is the same as the Edelbrock. I fabricated a small adapter to be able to use the stock throttle link with the Carter. It worked fine for several years until I got tired of the surging I got with the mechanical linkage. I just replaced the mechanical linkage with a Lokar throttle cable. Went out Sunday with it and it works great. I have the old throttle linkage. If you're interested, send me a PM.

Don't give up on the Edelbrock carb for off-road use. There are mods that can be done to greatly improve off-road performance. I have a Word document that is part of a thread I copied from Pirate4x4 that explains a lot of the mods to be done. PM me your email and I'll send it to you.

 

[Mherriford]

Somebody was just talking about this linkage a little while ago, but I do not remember which forum it was on, either way I do not think that it would be hard to swap over to a regular style between the firewall and carb

 

[Naildriver111]

I had a similar problem with my stock carb, the heater hose was up against the passenger side of the carb where the high idle cam connects to the throttle plate, causing it to stick at highway speeds, I re-routed them to the fender.

 

[Broncobowsher]

That funky linkage is a throttle equalizer. it is there to give a steady throttle control regardless of engine and body movment. It reference the gas pedal to the firewall and gives that movment between the intake and the throttle butterfly. Neat idea and worked fairly well when all the linkage is working right.

Today the fix is to usually just put on a throttle cable. Does the same function and is simplier.

As for the carb of choice. That is like picking what color you want to paint it. Many right choices and a few bad ones. Mostly personal preference. Some can screw up something that works perfect for most everyone else. Others can make the most hidious things work perfectly.

Half throttle... try unhooking the linkage and see if you can open it all the way. I wouldn't be surprise the linkage is messed up.

Sticking under accel... Check the motor mounts. The drivers motor mount lifts under acceleration. When it lifts the motor twists in the frame and can play with the linkage. On 351s the valve cover often comes up and hits the linkage right off the gas pedal, sticking it. Works perfect in the parking lot or low throttle settings but when you punch it, the motor lifts on that side and jams the linkage. On 351 that is common even with decent motor mounts.

 

[KDML]

I think I have the same linkage on my 1970. I was concerned with binding as well, but I drove it daily this past summer without any issues. Here is a link to my original thread. Let me know if you need any other pics:

http://classicbroncos.com/forums/showthread.php?p=794256#post794256

 

[Ohio Bill]

See if you have a manual throttle cable hooked to the linkage...like for PTO RPM's.....this could be stuck and causing the problem. I had that happen a few years ago was only getting 1/2 pedal.

 

[Slewis25]

It's starting to make sense now, thank you guys for all of the information. The truck originally had a PTO, which I have if anyone is interested in it, and there is a manual throttle nob on the left side of the dash, the cable is not hooked up but I think who ever installed the new carb did not connect the linkage properly, hense the half throttle and sticking. I plan on purchasing a cable type throttle to remedy the situation.