Over revving.

[Pete54]

Guys, I have a problem with my throttle sticking. On odd occasions whilst driving the auto choke revs the motor up and won't return to normal. Usually I have to put it in neutral and pull over then kick the accelerator pedal flat to the floor for it to kick down. Any idea's on what is wrong. I am pretty green on the motor stuff btw. Thanks to all who respond!

[bob k. mando]

you should always tell us what you've got when you're asking a question. you may have multiple cars and you can't expect us to read your mind to figure out which one you want to know about.

are you sure your throttle return spring is good?

have you tried getting your foot UNDER the throttle pedal and LIFTING?

the 54 Special should have a 264ci Nailhead which is just a small bore 322ci. both of these engines are the 'short deck' block.

we don't have a shop manual for the 322 but the 57 has a 364ci Nail which is the mid-deck block and will be quite similar.

http://www.teambuick.com/reference/library/57_chassis/

[Pete54]

thanks for the info. sorry I'm really new to these forums so it will be learn as I go. I have a 54 special 4 door. 264 with the dynaflow slush box I tried the foot under the pedal and that didn't work it just kept on revving. Does the dash pot have anything to do with a problem like this? Someone suggested a broken spring and that I could replace that with an electric choke on the stromberg 97 carb. The spring is not broken according to the fellow who put the carby together. Thanks for your time Bob.

[suntreemcanic]

Inspect all the linkage and look for something that could be touching it or laying on it. Move it by hand and wiggle it at the joints to see if it is worn or hanging up. If the choke is causing the problem maybe there is a spring broken or missing that lets the choke activate the fast idle when you are driving it and the engine is warm. It is a mechanical problem and I am sure with a little time and study you can fix it.

[bob k. mando]

I tried the foot under the pedal and that didn't work it just kept on revving.



that's no good. i'm not really sure how the *choke* should force it to rev? it doesn't matter how much fuel you throw down the venturi throat, if the primary/secondary butterflies aren't opening the engine CANNOT get any air. it'll just die due to flooding.

yeah, like suntree says, there's got to be a cause for this. those old cars aren't automated enough to pull a Christine on you.

i doubt it has a throttle cable ( instead of a link bar ), but if it does, make sure that the cable is well lubed and moves easily. i had a motorcycle throw me one time because the throttle return cable ( cars don't have, cycles use a return cable instead of a spring to pull back on the throttle ) was rusted up inside the sleeve and wasn't pulling back on carb link.

if it's a link bar setup, make sure that the bars move freely and without interference through the whole range of motion. have somebody step on the throttle for you while the hood is up and the engine is off.

once you've verified that the simple stuff isn't the problem, then worry about tearing the carb down.

we don't have a 54 shop manual, but we do have the 57. this still covers a Nailhead, but it's the 2nd gen 364ci. should still be many similarities to what you have.

http://www.teambuick.com/reference/l...hassis/3-a.php

[telriv]

Another thing to check is the linkage that goes to the trans. accumulator on the left front of the trans. the side the steering wheel is most likely on. Otherwise if it's right hand drive it will be on the opposite side. There's not much to these old linkage set-ups to go wrong. Many times it's the lack of a strong enough spring or no spring. On ANY carb/trans linkage there should be NO lubricates as that attracts dust & makes things stick.


Tom T.

[TexasJohn55]

After engine is hot, remove the air cleaner and see if the choke butterfly is standing straight up with engine off. Loosen screws on choke cover,make note of where it is aligned with marks and arrow, rotate it left and right and see if the choke butterfly opens and closes correspondingly, if it does, set it 2 marks toward lean from where you started and try it. While you are there you can see if the choke fast idle linkage is free and working and that it is not on fast idle ramp of the cam.

With a warm engine you should be able to crack open the throttle and the choke blade remain straight up and down. If it cocks slightly, it will pull fast idle linkage and make it idle too fast.

If you have a dashpot, try forcing the throttle to idle position and see if the dashpot is adjusted too tight and holding it off base idle screw. If the dashpot is adjusted too tight, it will spring back when forced to idle and released, provided that the throttle is not resting on fast idle cam.

You really need to aquaint yourself with all that by hands-on after reading your shop manual. YOU DO HAVE A MANUAL DON'T YOU?

[Pete54]

I do have a manual and will now (in the the time I have) explore these idea's further. Re the dash pot, whilst the engine was revving high I pushed the pot in a little and there seemed some play and the revs dropped off, hence my query with that part. I will explore further, thank you gentlemen, much obliged.

[bob k. mando]

oh, a also check link bar movement with the air cleaner installed.

if the bar is binding up on the bottom of the filter housing the source of the problem may actually be that your engine mounts are shot.