Hard Starting 300
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4wd Low
Joined: Oct 2023
Posts: 14
Likes: 5
Hard Starting 300
I have a 67 F350 with a 9 ft grain bed, with a straight six and a four-speed.. Had the truck a couple of weeks, did some searching on here and still can't figure out my problem. Fires right up when it's cold. You can shut it off &10 minutes later it won't restart for anything until it's cold again.. Start it up and drive it around the block and back,maybe 10 miles and it turns over real slow and won't restart then either. Brand new battery and had the carburetor rebuilt, run's normal other than restarting, Not sure where to start looking otherwise.
Last edited by Lots of old trucks; Oct 8, 2023 at 06:28 PM. Reason: Wrong word
Mountain Pass
Joined: Apr 2013
Posts: 138
Likes: 18
From: Moriarty, NM
Id start with the starter and battery cables. Make sure they are all clean and tight no corrosion. I would remove the starter and inspect the bendix gear and the bushings. When they get dry they tend to drag a little.
I would then look at carburetor and see if the fuel is boiling out of bowl when hot and shut off. Also check float level making sure it aint flooding after shut off.
I would then look at carburetor and see if the fuel is boiling out of bowl when hot and shut off. Also check float level making sure it aint flooding after shut off.
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4wd Low
Joined: Oct 2023
Posts: 14
Likes: 5
Thanks for the info, I did take the cables all off today and polished them up with my wire wheel.. Took the bolt out of the block, and cleaned it up as well where it grounds to the engine. I got a AMC Jeep style fuel filter to put on with the three nipples, I seen some videos on YouTube where you run the third nipple back to your tank to get rid of the vapor. I have a 62 C series grain truck as well, It used to vapor lock ,but I put one of the little pulsating electric pumps on to go with the manual and it quit..
Logistics Pro
Joined: May 2015
Posts: 4,474
Likes: 974
From: Tri Cities, TN
You may need to replace the starter. The Autolite/Motorcraft direct engagement starters draw a lot of current 150-200 amps. If the bushings are worn which they likely are, and the starter drive plunger pivot is worn the starter drive plunger can contact the armature when the starter engages. This will cause it to draw more amperage than the battery can supply.
Also, you might want to check the initial timing if it is too far advanced that will cause an engine to crank slow or kickback when it is hot. The initial timing for a 300 I6 manual trans is 6 degrees before TDC.
Also, you might want to check the initial timing if it is too far advanced that will cause an engine to crank slow or kickback when it is hot. The initial timing for a 300 I6 manual trans is 6 degrees before TDC.
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4wd Low
Joined: Oct 2023
Posts: 14
Likes: 5
I was kind of leaning towards the starter, It turns over pretty fast when the engine is cold. Yeah I can drive at 10 mi and come back home. Turn the key and it barely turns over. I was also doing some reading on the timing and if I want to retard the timing, I turn it clockwise if I remember correctly.
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FTE Legend
Joined: Nov 2015
Posts: 30,964
Likes: 4,130
From: Angier, NC
I run 10* BTDC and as much as 14*BTDC on my 300 six with no kick back but at 14* I had pinging and why it is at 10*
If I went back more it took more cranking cold or hot before it would fire up.
Even with good clean cable connection the cable can have high resistance and the only way to check is a voltage drop test.
Once you have it cranking over at speed we can look into the hot restart issue.
Yes I do have hot restart issue too.
Dave ----
If I went back more it took more cranking cold or hot before it would fire up.
Even with good clean cable connection the cable can have high resistance and the only way to check is a voltage drop test.
Once you have it cranking over at speed we can look into the hot restart issue.
Yes I do have hot restart issue too.
Dave ----
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Laughing Gas
Joined: Oct 2022
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Likes: 184
So many things here. You have to be diligent and not just throw a parts cannon or guess at it.
You need, fuel, air spark, timing and rotational speed to start it. You say its slow to turn over after you shut it off. How slow? Do you have spark at that point or have you checked? Have you pulled plugs to see if it spins any faster?
Regardless it seems to be some heat related issue. Cables, solenoid, coil, charging system etc. All of that needs tested. Work one system through at a time and make sure it's good.
Report back as you go. Slow speed I would check to make sure you aren't hydro locking or partially locking, verify all cables are good as Fuzz said. Check the solenoid etc. Hot restart would be easy to test solenoid because you can just shove a wrench between the terminals.
Let us know.
You need, fuel, air spark, timing and rotational speed to start it. You say its slow to turn over after you shut it off. How slow? Do you have spark at that point or have you checked? Have you pulled plugs to see if it spins any faster?
Regardless it seems to be some heat related issue. Cables, solenoid, coil, charging system etc. All of that needs tested. Work one system through at a time and make sure it's good.
Report back as you go. Slow speed I would check to make sure you aren't hydro locking or partially locking, verify all cables are good as Fuzz said. Check the solenoid etc. Hot restart would be easy to test solenoid because you can just shove a wrench between the terminals.
Let us know.
Thread Starter
|
4wd Low
Joined: Oct 2023
Posts: 14
Likes: 5
So many things here. You have to be diligent and not just throw a parts cannon or guess at it.
You need, fuel, air spark, timing and rotational speed to start it. You say its slow to turn over after you shut it off. How slow? Do you have spark at that point or have you checked? Have you pulled plugs to see if it spins any faster?
Regardless it seems to be some heat related issue. Cables, solenoid, coil, charging system etc. All of that needs tested. Work one system through at a time and make sure it's good.
Report back as you go. Slow speed I would check to make sure you aren't hydro locking or partially locking, verify all cables are good as Fuzz said. Check the solenoid etc. Hot restart would be easy to test solenoid because you can just shove a wrench between the terminals.
Let us know.
You need, fuel, air spark, timing and rotational speed to start it. You say its slow to turn over after you shut it off. How slow? Do you have spark at that point or have you checked? Have you pulled plugs to see if it spins any faster?
Regardless it seems to be some heat related issue. Cables, solenoid, coil, charging system etc. All of that needs tested. Work one system through at a time and make sure it's good.
Report back as you go. Slow speed I would check to make sure you aren't hydro locking or partially locking, verify all cables are good as Fuzz said. Check the solenoid etc. Hot restart would be easy to test solenoid because you can just shove a wrench between the terminals.
Let us know.
Lead Driver
Joined: Jul 2017
Posts: 9,616
Likes: 1,183
From: San Jose, CA
I don’t think vapor lock should cause slow cranking. Long cranking, maybe, but not slow cranking.
Have you checked ignition timing yet?
When it cranks slowly, have you disconnected the vacuum advance to see if it changes?
And speaking of… Do you know if the vacuum advance is connected to full manifold vacuum, or timed/ported vacuum?
Is it still a points distributor, or has it been converted to electronic?
In spite of the newly cleaned and tight battery cable connections, what gauge are your cables, and how old are they?
Have you checked ignition timing yet?
When it cranks slowly, have you disconnected the vacuum advance to see if it changes?
And speaking of… Do you know if the vacuum advance is connected to full manifold vacuum, or timed/ported vacuum?
Is it still a points distributor, or has it been converted to electronic?
In spite of the newly cleaned and tight battery cable connections, what gauge are your cables, and how old are they?
Thread Starter
|
4wd Low
Joined: Oct 2023
Posts: 14
Likes: 5
I don’t think vapor lock should cause slow cranking. Long cranking, maybe, but not slow cranking.
Have you checked ignition timing yet?
When it cranks slowly, have you disconnected the vacuum advance to see if it changes?
And speaking of… Do you know if the vacuum advance is connected to full manifold vacuum, or timed/ported vacuum?
Is it still a points distributor, or has it been converted to electronic?
In spite of the newly cleaned and tight battery cable connections, what gauge are your cables, and how old are they?
Have you checked ignition timing yet?
When it cranks slowly, have you disconnected the vacuum advance to see if it changes?
And speaking of… Do you know if the vacuum advance is connected to full manifold vacuum, or timed/ported vacuum?
Is it still a points distributor, or has it been converted to electronic?
In spite of the newly cleaned and tight battery cable connections, what gauge are your cables, and how old are they?
Thread Starter
|
4wd Low
Joined: Oct 2023
Posts: 14
Likes: 5
(UPDATE)
10-11,Put the new Jeep-Amc 3 nipple bypass fuel filter on tonight. 3rd fitting goes back to filler neck behind seat. Let run 15 minutes,shut off,let heat soak,started back up over and over ❗ With it running I could shine a flashlight down in the tank and see the excess fuel and vapor coming back in to the gas tank.
10-11,Put the new Jeep-Amc 3 nipple bypass fuel filter on tonight. 3rd fitting goes back to filler neck behind seat. Let run 15 minutes,shut off,let heat soak,started back up over and over ❗ With it running I could shine a flashlight down in the tank and see the excess fuel and vapor coming back in to the gas tank.
FTE Legend
Joined: Nov 2015
Posts: 30,964
Likes: 4,130
From: Angier, NC
You need to do a voltage drop test when the hard / slow cranking happens https://www.ford-trucks.com/forums/1...w-starter.html
This test will show just where the trouble is with out throwing parts at it. If it is a bad starter the test will show it.
Now if you can get it to crank over fast when hot and it has to crank a long time before it fires up its not really a vapor lock but heat soak of the carb.
The heat boils the gas in the carb bowl and the way I see it gas vapor being heavier than air goes in to the intake and "floods" the motor.
I bet when it dose fire up it acts like it was flooded? If you hold the throttle wide open it should start a little faster.
A fix is to keep the carb as cool as you can.
On the 300 the exh manifold is bolted to the intake to heat it to keep the air fuel in a vapor, If the intake is to cold the fuel can drop out of the air and have the motor run poorly.
There is also a valve in the exh manifold that when the motor is cold puts more hot exh to the intake. As the motor heats up the valve should open and keep the hot exh from hitting the intake and heating it. You have to make sure it moves as it should or wire it open.
I also have a 300 and it has a hot restart issue I just hold throttle wide open and it dose not crank as long before it fires up.
Dave ----
This test will show just where the trouble is with out throwing parts at it. If it is a bad starter the test will show it.
Now if you can get it to crank over fast when hot and it has to crank a long time before it fires up its not really a vapor lock but heat soak of the carb.
The heat boils the gas in the carb bowl and the way I see it gas vapor being heavier than air goes in to the intake and "floods" the motor.
I bet when it dose fire up it acts like it was flooded? If you hold the throttle wide open it should start a little faster.
A fix is to keep the carb as cool as you can.
On the 300 the exh manifold is bolted to the intake to heat it to keep the air fuel in a vapor, If the intake is to cold the fuel can drop out of the air and have the motor run poorly.
There is also a valve in the exh manifold that when the motor is cold puts more hot exh to the intake. As the motor heats up the valve should open and keep the hot exh from hitting the intake and heating it. You have to make sure it moves as it should or wire it open.
I also have a 300 and it has a hot restart issue I just hold throttle wide open and it dose not crank as long before it fires up.
Dave ----
Thread Starter
|
4wd Low
Joined: Oct 2023
Posts: 14
Likes: 5
You need to do a voltage drop test when the hard / slow cranking happens https://www.ford-trucks.com/forums/1...w-starter.html
This test will show just where the trouble is with out throwing parts at it. If it is a bad starter the test will show it.
Now if you can get it to crank over fast when hot and it has to crank a long time before it fires up its not really a vapor lock but heat soak of the carb.
The heat boils the gas in the carb bowl and the way I see it gas vapor being heavier than air goes in to the intake and "floods" the motor.
I bet when it dose fire up it acts like it was flooded? If you hold the throttle wide open it should start a little faster.
A fix is to keep the carb as cool as you can.
On the 300 the exh manifold is bolted to the intake to heat it to keep the air fuel in a vapor, If the intake is to cold the fuel can drop out of the air and have the motor run poorly.
There is also a valve in the exh manifold that when the motor is cold puts more hot exh to the intake. As the motor heats up the valve should open and keep the hot exh from hitting the intake and heating it. You have to make sure it moves as it should or wire it open.
I also have a 300 and it has a hot restart issue I just hold throttle wide open and it dose not crank as long before it fires up.
Dave ----
This test will show just where the trouble is with out throwing parts at it. If it is a bad starter the test will show it.
Now if you can get it to crank over fast when hot and it has to crank a long time before it fires up its not really a vapor lock but heat soak of the carb.
The heat boils the gas in the carb bowl and the way I see it gas vapor being heavier than air goes in to the intake and "floods" the motor.
I bet when it dose fire up it acts like it was flooded? If you hold the throttle wide open it should start a little faster.
A fix is to keep the carb as cool as you can.
On the 300 the exh manifold is bolted to the intake to heat it to keep the air fuel in a vapor, If the intake is to cold the fuel can drop out of the air and have the motor run poorly.
There is also a valve in the exh manifold that when the motor is cold puts more hot exh to the intake. As the motor heats up the valve should open and keep the hot exh from hitting the intake and heating it. You have to make sure it moves as it should or wire it open.
I also have a 300 and it has a hot restart issue I just hold throttle wide open and it dose not crank as long before it fires up.
Dave ----