Hello all, new guy here. I have a 1947 1/2Ton with a straight six G series engine. Very nice truck and love to drive it. Trouble is it is ornery as hel when trying to start cold. I initially thought all my problems were fuel related. Installed rebuilt mechanical fuel pump, rebuilt carb to no avail. Installed electric fuel pump with low pressure regulator (3-4 psi) inline from gas tank....I thought that would do it....nope. Has new battery and has spark. Turns over good...until the battery draws down. Eventually it will start but wow what a PITA just to fire it up. Sometimes I have to resort to gas/ether in carb or bump starting. I have been throu the forum archives and have pretty much hit everything you all have mentioned. I am kinda at a loss right now. Anyone think electric?
Thanks, Tom

 

if you have to ad gas or either to the carb, something isn't working like it should, is the choke going all the way shut, with the breather off, and look down the carb when you move the throttle linkage, do you see gas squirt down the carb bore?

 

welcome !!! mine was hard to start because of low compression ,since rebuilt it starts real good .if it starts by pouring gas in carburator it has to be gas related ! is it just cold .

 

Thanks for input
I just started it a few minutes ago. It gets gas when I stroke the throttle and the choke does close tight. It just took forever and thats with me pouring some gas in the carb. Once it starts it purrs like a kitten. It was cold temp out about 55. Cant be good for the starter to work that hard. I only give it 5 second tries.

 

"welcome !!! mine was hard to start because of low compression ,since rebuilt it starts real good .if it starts by pouring gas in carburator it has to be gas related ! is it just cold"
Temp is about 55 so I suppose that could be considered cold. Engine rebuild was not in the cards just yet but.....I think if it came to that I would consider a V8 switchover first. Thanks!

 

Might try cranking it over, while it's turning, pump the throttle 2 times and give it a quick choke, they all start different.

 

You did not say how long between it last ran?
Is it a week between starts or over night?
If once started and you run it for a bit, say a mile or 2 then shut it off will it start right back up?

I ask because today's gas blend is not made for motors with carbs and causes all kinds of issues from hard starting if left sitting for a week or more, to hard stating when hot.
The hard if left a week or more is because the fuel in the carb evaporates so you have to crank / turn the motor over a lot more to get fuel from the tank and fill the carb before it will start. Someone said to pump the throttle when cranking this way once the carb has fuel it will squirt it down the carb and fire up.
I have to do this with my 81 F100 with a 300 six if left more than a week not running.

As for the hot hard start again it's the fuel blend.
The fuel in the carb boils / vaporizes easier and the vapors fill the intake so when you go to restart the motor is now flooded.
If you hold the throttle wide open it will start easier as it is pulling in more air than fuel.

To help fight this you want to keep the carb as cool as you can.
A thick plastic carb spacer helps if you have the room.
2 thicker gaskets with a pan under the carb helps keep heat off the carb.
On v8's if the intake has a cross over to heat the intake plug this off.
On a six the exh & intake are bolted together but there is a butterfly valve that directs exh gases to the intake.
You need to make sure this is working and / or wire it open so exh dose not blow on the intake.

All of the above also happens to others on FTE, do a search in the other areas to see what others have done to help with the issue.
Now if you drive your truck when it is cold out you may need to warm it up a little more before you can drive as the heat on the intakes help keep the fuel a vapor. I do not have any heat to my factory log intake and I have driven it when 20*f out side with out any issues but each motor / truck is different as someone said.
Good luck
Dave ----

 

Dave, thanks for all the good info. Update 15 mins ago. I had the truck running two days ago after much effort. I was struggling to start it today and was going to quit for the day. I put it on the charger and while I was looking it over I noticed the Intake/Exhaust crossover valve (correct name?) you mentioned was loose and not in any particular position. I wired it in the forward position (closed?). I then was able to start the truck. I was thinking maybe that's the problem but then realized I was still charging the battery and the extra boost might have done it. So, I will try and find a new spring for that valve and solve that first. If that valve was malfunctioning do you think that would be a big problem?
Next I need to think about something electronic because even though i have spark and it runs perhaps it's not enough. Guy down at the engine rebuild shop mentioned they solved the hard starting with a Pertronix electronic "points". I notice some folks also use the pertronix "Flamethrower" coil.
Not sure but I will keep plugging away and appreciate the tips. Speaking of modern fuel and it's problems is there a good additive you might recommend?
Thanks! Tom

 

The only time I think a intake heater be it a cross over on a v8 or the butterfly on the exh to force heat to the intake on a six would be a problem if the heat was on all the time is overheating the carb when running or on a hot start.
If the motor was cold from say sitting over night or 2 then maybe not but ..........

If the heat was on all the time to the intake and heating it then when you shut down the heat could boil or vaporize the fuel in the carb so the bowl is empty.
There is a way to check if the carb bowl is empty. Before starting pull the filter and move the throttle and see if you see gas squirt.
If no gas then it is boiling out and the carb needs to be insulated from the intake & the heat.

You running points and is this 6v or 12v system?
If points is the dwell set right, I dont like going by point gap as the dwell can be off.
I dont know how they have a 6v system set up but the later 12v system run 12v to the coil when cranking / starting and once the key is let off to run the resistance wire takes over at less volts.

The factory runs a wire from the solenoid "I" stud to the coil to get a full 12v when cranking.
So if you dont have this I would look into running full 12 volts to the coil when cranking and if running points the dwell set right and see how it goes.

I have heard good things on the point replace kits.
I have an old Mallory kit, no longer made, that replaced duel points in a Mallory dist. and it ran good but I dont know if it started any faster as the swap was done before I started using the dist. and it was in drag motor to start. It was then used to replace a bad electronic setup as I needed to move the car.
Being lazy and the car now running I left the Mallory dist. in it.

I also have another car with a Mallory duel point dist. and it fires right up every time and will not replace it unless I really have to.
So if all the above checks out then I would look into the point replace kit.
Dave ----

 

Dave, thanks for all the good knowledge.

My truck is mostly original.... 6v positive ground, original distributor etc...

One thing you mention and I think is a problem is heat transfer from manifold to carb. Last year, I drove into town one hot day and ran into the store for less than 10 minutes. When I came out I was unable to start the truck and had to bump start it. Based on what you say I think that it was vapor locked. I may try and add an additional gasket and see if it helps. You also mentioned a pan?

I still am looking at the intake heater and suspect it might be at least part of the problem. I am really struggling to find any info on that valve and wonder if anyone actually sells parts for it even if it is faulty. How critical is that valve and can it be disabled. I sprayed some penetrating lubricant on it in anticipation of inspecting it....its really heat/rust baked and in rough shape.

I have not messed with distributor yet since I had spark and was so convinced it was fuel delivery....probably a troubleshooting mistake to be so focused on one thing. As far as the Pertronix igniter I need to talk with the company to find out which one I need since I think I may go that route. They must be pretty busy as I was on hold for 20 minutes and then was hung up before I ever reached a real human. I really like the idea of the reliability.

I appreciate all the great info and will keep plugging away on it until I can drive it somewhere and not get stranded!

Thx, Tom

 

Still chugging away on the hard start. As mentioned by people in the thread they had compression problems so I tested the compression today.
Cold engine, no throttle and elevation about 3400'. I tested each cylinder three times. All of them were consistent at 70 - 88 with an avg on each of 80. Does that sound low?
Thanks!

 

Throttle open or closed when testing? Should be wide open for test.

 

That was closed. I will test it wide open next chance I get. Thx!

 

Sorry I am a little late getting back on the pan as it is called.
It goes between the intake & carb so any heat is directed away from the carb.
I know they make them for v4 carbs and if you look it up you will see what it is and maybe you can make one to see if it will help.

What happens if I did not post it before when the motor is off the carb gets heat soaked and the fuel in the carb boils.
The fumes being heavy go into the intake manifold and cause it to "flood".
Most of the time if you hold the throttle wide open like you would a flooded motor it will start faster.

The thing is to keep the carb as cool as you can so the fuel dose not boil.
Also to see if on the right track go for a drive and return home.
Pop the hood and put a bag of ice cubes around the carb and close the hood.
About 10 min later remove the bag of ice and see if it will start easier.
If it dose then you know you need to keep the carb as cool as you can when it sits when hot.

Just another thought have you tried a different brand of gas?
If you always get ges at XXY brand next fill up get gas at YYX brand.
Not a different place but a different brand and see what that dose.
Dave ----

 

Dave, thanks for the info. I will try those ideas and see if I can find a pan or make one. As far as gas goes you are the third person to mention that. I will try something else next time. I had been using premium. Thx!