Help asap 350 won't start

[Squareforceone]

I don't know whats wrong with this bastard i just put a new motor (350) in my 84 i went to take it on its first drive since the motor install and it won't start. I got in it today started it easy enough let it idle for a few minutes the thing ran fine then i got it put it in gear and pulled it forward a bit it was still running fine. I pulled it forward a bit stopped to make sure breaks were working then pulled forward a bit more and it started running a bit rough and then died. Now i can't get to run again. I tried a bunch of times i did finally get it to run for a bit but the only way it stayed running was by me pumping the hell out of the gas as soon as i let for a second it died… I don't get it was running fine and idleing earlier today now it won't run. It tries to fire while cranking but won't. Could it be because it's cold outside it is like 17 degrees right now..

[68Timber]

New motor as in new to you, or fresh rebuild?

[Squareforceone]

new to me but fairly fresh only a few thousand miles why?

[Squareforceone]

I used my old carb btw

[68Timber]

Originally Posted by Squareforceone

new to me but fairly fresh only a few thousand miles why?

Uh, cause I seen it happen to the dudes on Fast and Loud the other night. It was a fresh rebuild and wiped a lobe IIRC, died pretty much the way you describe. With a few thousand miles on the motor that probably is not your problem.

[Squareforceone]

yeah cams broke in

[clapage6]

My truck did this when my holley's floats would stick allowing the excess fuel to flood the carb. It would be a bear to restart until all the fuel had evaporated... flooding is what's causing your hard restart I would think.... or check for the obvious stuff :-p grounds/ignition wires etc

[suxtobu65]

Clogged fuel filter? Not enough fuel to meet demand.

[RastaRobb]

How about timing? Did you get the distributor bolted down good? If it shifted on you it could certainly behave like you say.

[RastaRobb]

Suxtobu65, who I am sure means nothing personal, might be on the right track with fuel filter. How about the pump?

[Squareforceone]

i think it may of just been a problem with the choke grrrr idk whats wrong with my choke it never has worked right tried adjusting it a thousand times… went back over and started right up let it idle for a few minutes and it sound like it was going to die so i shut it off and adjusted the choke to being open and it worked well enough for me to drive it a mile or so back to my house.

[suxtobu65]

Sometimes the cold amplifies little problems.. Like mentioned also, pump could also be a problem, probably more likely than the filter actually.

[geezer#99]

It's not your choke, your filter, your pump, your dizzy, your timing or your float!
It's a cold intake plenum and cold air intake. You need heat in both the incoming air and heat in your intake plenum from the crossover from the exhaust to make it run until you get enough heat transfer to keep the intake warm and the fuel vaporized.
The vaporized fuel from your carb reverts back to a liquid as it flows along the cold walls of the intake. The fuel puddles in the plenum, you run lean to your cylinders and the motor runs rough and dies.
The last time you started it and let it idle till it started to run rough, shut it off to play with the choke helped when you re-started it and drove it home. During your shut down time you got some heat soak from your motor. Hot air rises from the warmed up oil and the conductive heat from the heads. The heat soak allowed the plenum to warm up enough to keep the fuel vaporized.
My truck and several motors I've had all did this in colder winter air (40F and below) Headers eliminate the crossover and hot air for the air cleaner.
I expect it to run like crap until it's had a good heat soak.
My cure is start it up, run for a few minutes, shut it off for 5 minutes for a heat soak, fire it up for a couple minutes, kick it down and off I go. But then it's still possible in my first mile of driving for the intake to cool enough due to the increased cold air intake and run like crap again, so I run down the road in second to keep the rpm and the airflow up, pop it into nuetral and keep the rpm up at the first stop in case it wants to quit. Usually good after that.
It's the nature of the beast!
I expect it and react accordingly.