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Author Topic: BLACK SMOKE AFTER WARM UP 1978 2wd chevy c10 V8 305 2brl  (Read 2305 times)

Offline Dave W

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BLACK SMOKE AFTER WARM UP 1978 2wd chevy c10 V8 305 2brl
« on: April 25, 2019, 04:38:10 PM »
I have a 1978 chevy c10 2wd 305 2brl
It was sitting for a few years before I got it.
I changed the whole fuel system tank to carb
Got it running it seemed fine.
Now it starts fine when cold, if I shut it off after 5min
and try to restart it, forget it barely runs (rough) and black smoke
Comes from tail pipe.
Wasn't doing it before.
Any ideas??
Thank you in advance
« Last Edit: April 25, 2019, 04:43:41 PM by Dave W »
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Offline Dave W

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BLACK SMOKE AFTER WARM UP 1978 2wd chevy c10 V8 305 2brl
« Reply #1 on: April 25, 2019, 05:24:10 PM »
I have a 78 2wd c10 v8 305 2brl. it sat for a few years before I got it.
I changed the whole fuel system tank to carb
Got it running, and it seemed fine.
Now it starts fine cold, it I shut it off after 5 minutes, and restart it
It barely runs and pours black smoke out the tailpipe.
Any ideas??
Thank you!!
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Online bd

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Re: BLACK SMOKE AFTER WARM UP 1978 2wd chevy c10 V8 305 2brl
« Reply #2 on: April 25, 2019, 11:11:28 PM »
Did you replace the carburetor or overhaul it?  There could be some fine debris caught in the inlet seat that prevents proper sealing of the needle or the float level may be high.
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Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline Dave W

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Re: BLACK SMOKE AFTER WARM UP 1978 2wd chevy c10 V8 305 2brl
« Reply #3 on: April 26, 2019, 04:29:37 AM »
Replaced it
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Offline Dave W

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Re: BLACK SMOKE AFTER WARM UP 1978 2wd chevy c10 V8 305 2brl
« Reply #4 on: April 26, 2019, 06:35:24 AM »
Yes, the carburetor is new replaced.
Seemed fine a week ago.
Not sure if the choke is staying closed,
or something like that.
Any thoughts?
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Online bd

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Re: BLACK SMOKE AFTER WARM UP 1978 2wd chevy c10 V8 305 2brl
« Reply #5 on: April 26, 2019, 08:59:10 AM »
If you think it's the choke, remove the air cleaner when the symptoms arise and look to see whether the choke is open or closed.
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Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline JohnnyPopper

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Re: BLACK SMOKE AFTER WARM UP 1978 2wd chevy c10 V8 305 2brl
« Reply #6 on: April 26, 2019, 03:45:27 PM »
"it starts fine when it's cold"

What happens when you "don't" shut it down after 5 minutes? Does it reach operating temperature.

Pretty sure the choke is the culprit.
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1957 Apache 3100 235 Inline 6, 3 on the tree
1973 C-20, 3+3 454 4BBL TH400  Water Injection
1978 K-10, 350 4BBL TH350 NP203 M.M. Part time Kit/Hubs
1980 C-10 under construction

Offline Dave W

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Re: BLACK SMOKE AFTER WARM UP 1978 2wd chevy c10 V8 305 2brl
« Reply #7 on: April 27, 2019, 10:21:30 AM »
It stays running ok.
The choke seems open a 1/8 of the way, never half or fully open.
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Offline JohnnyPopper

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Re: BLACK SMOKE AFTER WARM UP 1978 2wd chevy c10 V8 305 2brl
« Reply #8 on: April 29, 2019, 03:52:41 PM »
Bet you burn tons of gasoline!

Need to fix your choke man.... It's easier than looks.

Do a search on this site, lots of threads  for manual, heat riser, and electric chokes.
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1957 Apache 3100 235 Inline 6, 3 on the tree
1973 C-20, 3+3 454 4BBL TH400  Water Injection
1978 K-10, 350 4BBL TH350 NP203 M.M. Part time Kit/Hubs
1980 C-10 under construction
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