Another question on timing-

[enaberif]

Is there an electric throttle kicker involved?

Chokes have a stepped cam. When you trigger it the cam is on the highest level. As the choke opens the cam moves till the tab falls off and resumes normal idle.

If the choke remained on the high idle after opening it would be a crappy truck to drive.

[blazer74]

Ok, never seen a choke spring that could overcome the throttle return spring which is holding pressure on that stepped cam holding the high idle on a q jet until the throttle pressure on the cam is released.

Post 20

[philo_beddoe]

I tend to agree with blazer, it doesnt seem to ever want to come down on its own, like a modern EFI does. All i want to do is tap the pedal between 30 seconds and one min. and have the idle drop nice and easy. How should i adjust the choke dial, lean or rich?

[blazer74]

Other than me trying to explain why an electric choke wont kick down by itself, here is a post that explaind how they work from the beginning. Note the word tickle is use towards the end of the post (Fast idle cam and Fast idle screw)     http://www.chevelles.com/techref/Adjusting_Automatic_Chokes.htm

Carburated electric chokes will not drop off high idle or and other step of idle untill you touch (tickle the throttle)    Note the factory manual pic in post 20 from the person with the original question asked basically say the same thing.

[blazer74]

philobeddoe:  You need to get the proper documentation for adjusting the choke linkage from start to finish, Once your running  a blip of the throttle should drop the fast idle down to the next setting or step thanks to choke pull off  allowing the idle to come down some. It  will never do it by itself, the choke flap will open but thats it.
If the choke never comes off and idle never comes down at all your chock coil is bad or you have no power to it.

Lot of info on the net for this.

[blazer74]

099#msg273099 date=1450919101]

Enaberif



Chokes have a stepped cam. When you trigger it the cam is on the highest level. As the choke opens the cam moves till the tab falls off and resumes normal idle.


As you stated you must trigger the cam.

[philo_beddoe]

Well, what vile said makes simple sense too. A simple touch of pedal should disengage high idle. Mine does, but not quick enough. My carb is very clean, like new. No sticking issues.

[philo_beddoe]

Woops, i was typing as posts 35 and 36 came in. Stand by...

[blazer74]

Then it's not totally adjusted correctly. The link I put in earlier explains the relationship between the fast idle, choke pull off and kickdown after start.

[philo_beddoe]

Ok, as stated, my idle does drop down like it should, but not quick enough.

Got it, adjustment it is. First thing in the morning, i'll have a cold engine. I'll study that link and give it a try. Thanks.

[blazer74]

My original point from your question in post 20 is the electric choke is not totally automatic. It still requires driver input.

If you start up cold with the choke set to highest idle and don't touch anything, come back 30 minutes later and it will be screaming, it will not go to normal idle by itself.

[enaberif]

you trigger the fast idle cam at startup. after that it should idle down by itself once warmed up and require NO user intervention.

If your fast idle cam does not return  the engine to normal idle rpm then there is an issue somewhere that needs addressing.

you can manually override this of you wish but it should do it on its own. it is the point of the fast idle cam and the steps built into it.

[philo_beddoe]

You guys both have good valid points, i only tend to agree with blazer because i have never seen a GM factory v-8 (from the 70's) kick down entirely on its own.

However, my question STILL stands, what and how do i make an adjustment to make this fast idle drop down simply, quicker? Regardless whether the choke does it on its own or i have to tap the pedal.

[philo_beddoe]

Well, i read that link very carefully. And the guy that wrote it sounds like he knows what he's doing. I am starting to believe that my carb and choke is operating perfectly, like i said, it does kick down, but it takes a little longer than normal, probably due to the fact i have no heat riser valve in the manifold. I do however have a new heat stove unit and pre-heater hose to the air clnr assy snorkel.

It looks like the choke is not getting hot enough fast enough and maybe installing a heat riser valve will fix that.

I was hoping i could cheat a little and make a tiny adjustment and get the engine to kick down a little faster.

I think it works a lot like a grass trimmer or hand held leaf blower. You MUST lift that little choke lever and push the little clear rubber bulb to squirt a little gas in to start. If you push the choke lever down, it stalls out. But as that little engine warms up, now you can push the lever back all the way and your screaming and ready to go.

[philo_beddoe]

Weird how this post became a carb/choke issue, and totally got off the post title.  All good.