Smoke and miss at startup!

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KnuckleDuster

KnuckleDuster

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Even sitting a couple hours, I'm getting a rough idle and smoke on startup. Once I gas it for a minute and rev it a few times, all is normal and good with plenty of power and normal idle. Smoke is not really black or white, kinda dark gray.

I'm thinking valve stem seal leaking, but wanted to run it by you guys for ideas.

To further complicate the diagnosis, twice this week it revved up to 2000 rpms but went back to normal after blipping the throttle half a dozen times. Wondering if there is a possibility it could be carb/fuel related? Maybe a float or choke sticking?
Anybody been through this?


Thanks in advance!
 
Dark grey is fuel. Might be dripping into the intake from the float bowl.
 
Might sound 'elementary' , but what's the best way to check?
Look for puddles in the intake after sitting?
Trash in the carb or just crappy gas causing this?
Should I just pull the carb apart and blow it all out? Edelbrock 800cfm...
 
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If you have the knowledge to take it apart and put it back together, that would be a good place to start. If it is it has been on the car for a while, a new kit wouldn't hurt. Make sure you check the float level, check the float to make sure they are not holding fuel inside and sinking rather than floating. And replace the fuel filter.
 
You should be able to visually confirm it by lookin down the carburetor throat and seeing if it drips immediately after shut down.
 
I do. Thanks Roy. Martin and I pulled it apart about 1500 miles ago and checked the float levels. Martin only used it to break in a motor but we did find some trash in it.
I will pull the filter, its an edelbrock right at the carb hardline.
My tank is about ten years old, but no telling what junk is getting pumped in at the gas station...or what the ethenol laced fuel is corrupting in the carb.

Thanks to you also Rob.
 
Sho nuff. Carbureted fuel systems are simple. Edelbrock carburetors are real simple. You'll get it.
 
Man that ethanol is some bad stuff. I rebuilt my 1406 Edelbrock on my Dart and then let it sit to long, about 3 months, before I started it again. It ran like hell, so I took it apart again and man, you would have thought it had been on there 10 years! It was full of crud and nasty formations. Now I only run 90 octane ethanol free fuel.
 
There's a show in the morning, and it'll probably be 100° by the time I get home, so it might be Monday before I can tell y'all what I find, unless I just wake up real early, but I appreciate you guys helping me with the gameplan!

By the way Roy, where do you find fuel without ethenol?
 
You can look online. There's a site where you can enter your zip code and it will give you a list. It should come right up on a general google search for ethanol free fuel.
 
I'm pretty lucky I have several stations within a few miles of me that carry it. Most WAWA stations carry it.
 
Ok guys...started it up and had the GF help watch for smoke. I also was able to get out and look myself. The smoke looks more white than I remember from yesterday. It lasted about 2min with the car warming up on the electric choke. It was out of both banks but more on the drivers side.I let it warm all the way up and shone a light down all four carb barrels at shutoff...not a drop dribbling anywhere.
I was initially thinking valve seal but it would have to be multiple on both banks, no? (No exhaust crossover)
I'm not getting it.
 
Or just water vapor. Put a cool glass in the smoke and see if it condenses into water.

The 2000 RPM throttle hang up could be the throttle shaft or linkage or return spring(s). I'd be looking hard at that....it could be dangerous.
 
Does it have a very light blue tint? If so, that's oil probably from bad valve seals or guides.
 
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