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[Don.V]

I have a 82 C10 Silverado with a 305 and everything looks original. I believe I have a carb problem. My choke plate stays stuck open because it stay reving high. Hard to start up and struggles to turn off and the choke light stays on the whole time. I read any kind of smoke is bad but smoke does come out the mufflers and it smells like gas. This truck is hardly driven and I like to baby it. So far I've been owning it for 7 years. Please school me.

 

[Bfortune1000]

ive also had the same problem with my 86 with the 305, just dumps out white smoke when it strats up, same thing your talking about?

 

[89Suburban]

ive also had the same problem with my 86 with the 305, just dumps out white smoke when it strats up, same thing your talking about?

Mine does that. I stuck an exhaust flapper on the tailpipe held on by a hose clamp and park into the wind when idling.

 

[Jims86]

Don, I believe you probably need a new choke coil....they are pretty cheap, and the chokemits self needsnto be set.
where in Nor Cal are you?

 

[Jims86]

ive also had the same problem with my 86 with the 305, just dumps out white smoke when it strats up, same thing your talking about?

Brandon, does your white smoke go away when it warms up, or does it smoke all the time?

 

[DoubleDingo]

My Pop was a mechanic for nearly 40 years. The early 80's chevy's smoke a little upon start up. It is because the valve seals are o-ring type and not the good umbrella type. What happens is the o-ring allows a little oil between the seal and the valve stem and that little bit of oil settles on top of the valves. When you start it up white smoke blows out the tailpipe for a few seconds. It may not burn oil at an alarming rate, but it will burn off what settles on the valves. My truck does that and I plan to remedy the problem by switching engines. I have a BF Goodwrench 350 Crate engine sitting on the back patio that has about the same amount of miles as the engine in my '81 C20. Then I can switch the heads on the engine from the '81 engine to vortec for my '65, and the '81 will get an engine that won't smoke. I was going to switch the heads but decided it is easier to swap engines than it is to swap heads.

So, moral of the story, if it stops smoking a few seconds after start up then you have the o-ring type valve seals and need to replace them, or get better heads, or get an engine that has the umbrella type valve seals on the heads and switch engines.

 

[89Suburban]

Oil should be blue smoke, white is water.

There was some talk here about the choke light and all, I'll have to see if I can dig it up...

 

[89Suburban]

Here:

http://www.gmsquarebody.com/forum/showthread.php?t=4350&highlight=choke

 

[DoubleDingo]

Oil should be blue smoke, white is water.

There was some talk here about the choke light and all, I'll have to see if I can dig it up...

Re: Smoke, I agree about the color, but on mine smells like oil burning and I have to go with the word and knowledge of a seasoned veteran that knows how to diagnose and repair/rebuild any vehicle that has been produced. I have questioned him before and was proven wrong. And I am Not saying you don't know what you're talking about.

 

[89Suburban]

I know. And I am kind of guilty of this thread kinda bouncing all over the place about smoke colors. I'm just trying to help the original poster, he didn't even say what color it's blowing out. If he is smelling gas and the choke is sticking you would expect to see black smoke. So we really need him to stop back in and confirm what color smoke he is talking about since he did not initially specify. But just trying to simplify things to help him diagnose, general rule of thumb is blue smoke oil, white water, black unburnt fuel.

Now I am going outside to have a smoke...

 

[Don.V]

Don, I believe you probably need a new choke coil....they are pretty cheap, and the chokemits self needsnto be set.
where in Nor Cal are you?

Stockton.

 

[Don.V]

Yea, it's black smoke. Now when I start it, it stays revved up and shakes when I turn it off. While truck was on, I popped the hood open to check the carb and I see the choke plate stays open, even when I press on gas pedal here and there.

 

[Don.V]

I know. And I am kind of guilty of this thread kinda bouncing all over the place about smoke colors. I'm just trying to help the original poster, he didn't even say what color it's blowing out. If he is smelling gas and the choke is sticking you would expect to see black smoke. So we really need him to stop back in and confirm what color smoke he is talking about since he did not initially specify. But just trying to simplify things to help him diagnose, general rule of thumb is blue smoke oil, white water, black unburnt fuel.

Now I am going outside to have a smoke...

No problem.

 

[89Suburban]

If the choke plates are stuck open and it's blowing black smoke it's flooding. Been a while since I played around with carbs so hopefully someone else will chime in here on a possible source. First thing comes to my mind is needle valve off the float is not sealing, may me a piece of dirt stuck in it. High revving might be the step up cam off the chock linkage hanging up, or throttle return spring not doing it's job or vacuum leak? Shakes when you shut if off, with the flooding condition my guess is it's dieseling.

 

[Don.V]

Just want outside to start it for the first time but before I did took off the air breather and it start it up like a champ. Don't know sh!t bout carbs. I do see the coke plate staying open, dats my problem. Do I need a new carb or there's a way to fix it. I do have a Holley 4bbl carb that came off my brothers 69 nova 350 SS. He said he swapped it for a better Edelbrock and the Holley still works. I'll take pix later.