Bronco Forum - Full Size Ford Bronco Forum banner

1 - 14 of 14 Posts

·
Registered
Joined
·
242 Posts
Discussion Starter #1
Why is this dang motor so hard to start cold?? Timing is good, no vacuum leaks, anf it fires right up after it is warmed up. Does the fuel drain out the bowl when t cools down? Is my coil weak? Is it just a BB problem. I mean excessive cranking for almost 30 seconds...normally 3-5 non hit cranks for 5 to 7 seconds, then a few near hits then dies....then it lopes, catches, and finally idles. I just changed both fuel filters and tuned the carb....any ideas?
 

·
Registered
Joined
·
133 Posts
You could try a block heater or something to see if it's the warm vs cold or bc it sat for awhile. My money is on the carb being out of fuel. I would personally put a clear fuel filter right before the carb so you can see if it has fuel in it. No moisture on top of the intake manifold? And I assume mechanical fuel pump?
 

·
Registered
Joined
·
1,077 Posts
Its not a big block problem. My 390 fires right up even at 0. Sounds like you fuel pump is bleeding off. Put a clear filter on it like said above.What carb are you running?.
 

·
Premium Member
Joined
·
23,549 Posts
how much are you pumping the accelerator when it is cold?
 

·
Registered
Joined
·
242 Posts
Discussion Starter #6
how much are you pumping the accelerator when it is cold?
I don't pump it at all, or I try not to until I tire of cranking it. I have an Edelbrock 750 electric choke. I just rebulit it, and set the choke. Although this has been a problem since day one. I don't want to engage the fast idle kickout if I can help it, if that makes any sense, that's why I try not to pump it.
 

·
Premium Member
Joined
·
23,549 Posts
well no shit why it does not want to start.

pump the accelerator once to the floor, and try starting it.

carbs need to be pumped and have the throttle plates closed to start when cold. Well the choke is not needed when it is warmer out, but your engine will run better with it when cold.


Whats your reasoning for not wanting to pump it and set the choke?
 

·
Registered
Joined
·
242 Posts
Discussion Starter #8
You could try a block heater or something to see if it's the warm vs cold or bc it sat for awhile. My money is on the carb being out of fuel. I would personally put a clear fuel filter right before the carb so you can see if it has fuel in it. No moisture on top of the intake manifold? And I assume mechanical fuel pump?
Yes mechanical pump, and no moisture. Is the pump supposed to hold pressure, or bleed it back when off? It acts like there is no fuel
 

·
Registered
Joined
·
242 Posts
Discussion Starter #9
well no shit why it does not want to start.

pump the accelerator once to the floor, and try starting it.

carbs need to be pumped and have the throttle plates closed to start when cold. Well the choke is not needed when it is warmer out, but your engine will run better with it when cold.


Whats your reasoning for not wanting to pump it and set the choke?
I thought that if I pumped it too much, it will kick out of fast idle, which I DON'T want when it is colder out. The choke is set and operates fine, I guess I will have to pump it. I recently adjusted the fast idle up to about 1300 RPM'S; I haven't really tried pumping it since then, it's been 75 out. I will try first thing in the morning when I get home from work. Thanks,
 

·
Premium Member
Joined
·
23,549 Posts
it will never get fast idle if you do not pump it at least once to set the choke closed.
 

·
Registered
Joined
·
242 Posts
Discussion Starter #11
it will never get fast idle if you do not pump it at least once to set the choke closed.
Hrmm, that explains ALOT :rockon But isn't the choke already closed if it's cold? That's what is throwing me off

Thanks Jopes
 

·
Registered
Joined
·
2,153 Posts
The choke STAYS in the open position, when you shut the motor down, IF the motor is fully warmed up. When you pump the gas pedal, it allows the choke to close, and gives the engine a shot of fuel, via the accel pump.

To check this, remove the top of the air cleaner, and look at the choke, when the engine is cold. The plate should be open, UNTIL you hit the gas pedal once, just like the OE carb set up. My Bronco owners manual tells me to pump the gas before hitting the key.
 

·
Registered
Joined
·
242 Posts
Discussion Starter #14
Worked much better this morning, fired right up with a few pedal pumps, good deal, thanks again guys.
 
1 - 14 of 14 Posts
Top