First start of the day. Sputter, Lag for first 5 min

[Samuelpenner]

I bought a '76 C10 250 Inline 6 about 2 weeks ago and since day 1 I have had issues with cold start ups and just the first start up of the day. At first it would barely start, sputter, die and then start fine, sputter, lag for the first 5 min and then be fine... This is a project truck so I was planning on dealing with junk like this already. I started doing basic tune-up work (changed the plugs, wires, rotor, distributor cap, fuel pump, fuel filter, cleaned all the built up sludge off the engine and especially the starter, set the timing, cleaned/partially set the carb up) and it now starts up fine in the mornings for the most part but STILL lags and sputters for the first 5 minutes or so!! What could this be??

There are a few carb issues that I havent quite fixed yet. Maybe this is the reason?
1:I have not set the float in the carb and I know its probably not quite right
2:there is a piece on the carb the is hanging and obviously not set up right, but I havent messed with it because I'm honestly not too sure what it is... (this is probably the issue!! But I need to identify it first!!) I am thinking it must be the choke?? I attached a picture of the piece I am talking about. I am touching it with my finger.
3: The truck does not have a tachometer so when I set up the idle and fuel inlet(?) I was basically doing it by trial and error/whatever my maintenance manual said, minus setting a base for the RPMs...

I am not a mechanic by any means and have little experience with this stuff so please be patient as I learn Most of what I have learned so far is from online research, trial and error or putting to use the experience I have..

Let me know what you think!!!'


Thanks!!!

-Samuel

[81_Chevy]

sounds like the choke is set too tight.

[Irish_Alley]

def sounds like a choke problem

[bd]

Samuel,

That carburetor uses a divorced choke thermostat that bolts solidly to the manifold and connects to the lever that you're touching via a steel link.  It appears the link and perhaps the choke thermostat are both missing.  Hence, the choke doesn't close properly, making the engine run poorly until it warms up.

[Samuelpenner]

BD - thank you so much! That's a huge help. I figured that's what it was... The guy who owned it before me had sooooooo many rigged contraptions in the engine.. I just don't know the inline 6 250 or the carborator well enough to know what's missing..

Do you know of an online schematic for the carb so I can fix this?

[Samuelpenner]

Either way I will google that divorced choke thermostat and try to figure it out.

[bd]

76 CK Repair Manual - Go to Section 6M, pages 1-13.

[Samuelpenner]

Thanks!!!!