Engine dies while driving

[wildcard]

My 300 I-6 has started to just die while I'm driving.
It dies at slow speeds. Mainly when I slow down to turn and occasionally when I stop. It does fine out on the road.
I ran the idle up to try and help but it didn't make a difference. got me home though.
I don't know anything about a carb except to leave it alone. I replaced the coil today and got the timing set and it still does the same thing.
Could it be the fuel pump wearing out? I don't want to just keep throw parts at it. But I have no idea where to begin.

[Manny]

Time to check it with a vacuum gauge i would say just get an idea. Probably not the fuel pump as this would be more stalls out when under load not enough fuel to keep up with the motor. could be carb sloshing fuel into the intake. When it dies out is it instant restart or troubled. How does it act after the fact. Another thing does the truck have power brakes like when you hit the brakes its changing the engine vacuum. Finally does it sputter and die or sputter sometimes recover or is it like turning the switch off. 300 six is pretty solid just got something holding it back. Also don't fear touching the carb as the weather changes sometimes you may need to adjust to make it mix properly with the changing air conditions. Get back with us.

[wildcard]

I think I have it fixed. I changed the fuel filter. It had what looked like a really fine black powder in it. After that I ran about half a can of berrymans b12 through it. Then it decided it wouldn't idle. I turned the idle screw up but it still wouldn't idle. Finally I advanced the timing a couple more degrees to get it to keep running. I figured if it wasn't running right then I didn't have much to lose, so I started twisting on the carb adjusting screw. Then tweaking the timing a hair at a time til it sounded smooth at the exhaust pipe. Before, you could hear a miss back there that wasn't noticeable from the front of the truck. It's gone now also.
It idled and ran pretty good today. But it still seems like something is a touch off. It doesn't seem to have much power once it gets into 3rd gear.
I really appreciate the help and comments.

[Manny]

Glad your making progress. Hope she runs good and smooth for ya!

[M-100]

Glad it is doing better but you also said lt isn't as good as it could be. Check for vacuum leaks .i had a similar problem the other day . My carburetor was loose.

[gritlight]

I had a similar issue.i filled the full tank for me it was likely water in the fuel which fixed it self when I made sure it was full at all times.

[Ohiotinkerer]

This might be a long shot but I had similar problems with my 360 when it was warm out 2 summers ago and it turned out to be the gas cap wasn't venting and built up pressure in the tank - would cause it to run rough and it would die while I was driving - which is really fun when your in the left lane of a 4 lane highway doing 65.......

Don't know how warm its been where your at but mine only did it when it was above 75 degrees and sunny......

[WarEagle]

It idled and ran pretty good today. But it still seems like something is a touch off. It doesn't seem to have much power once it gets into 3rd gear.

Not sure if its fixed yet, bit it does sound like a vacuum leak. Mine did the same thing, the vac leak was in the carb around the throttle plates. As for the power, if you still have the 1bbl carb, that engine is probably starving for air and fuel. I swapped an Offenhauser dual plane intake and a Holley 4bbl on my 300, and the torque is unreal. Laid down a 2 tire burnout for 30 feet on my driveway!

Anyway, spray carb cleaner around your vac ports/lines/carb base and see if the idle changes. If it does, you have a leak.