53 F100 Flathead V8 239 not starting help
 

I have a 1953 F100 that i have and drive at least weekly for the past 2 years with relatively no engine problems. I purchased the car with the engine rebuilt/restored and I did the mechanicals/interior. I had the truck running the other day and backed out of my garage to go for a ride. The engine stalled out and now will not restart.

I am average at best with engines and do not know where to start to determine the problem. The engine cranks but will not turn over. Seems to be getting gas to the carb, but not 100% certain. Really want to tackle this on my own, but do not know where to start. Any help would be greatly appreciated. Should I start with the distributor/coil and if so, how?

Thank you

Re: 53 F100 Flathead V8 239 not starting help
 

First thing I'd check would be a look down the throat of the carburetor and operate the throttle to see if the accelerator pump is working. That will also indicate if there is fuel available in the float bowl. You can pull a plug and lay it against a ground source in the head someplace and turn the engine with ignition on then see if you get spark. With modern condenser quality being very poor these days, I tend to check it first if the spark in weak or non existent. Burned points would be the indicator of a bad condenser. A good rule of thumb is to start with the easy stuff first and hope it's something simple. Plugs could have gotten a bit fouled. A quick cleaning would remedy that.

Re: 53 F100 Flathead V8 239 not starting help
 

Thank you rotorwrench. I will give it a try and see. should I test the plug with a spark tester or does this only check the wire?

Re: 53 F100 Flathead V8 239 not starting help
 

What I've found to be helpful when chasing a issue is:

Start on the simple stuff. fuel,air,spark,grounds
Do one thing "change/test" at a time
Take some digital pictures as you go

Re: 53 F100 Flathead V8 239 not starting help
 

Thanks Tinker. I have some time Thursday and plan on starting with the fuel. I will also take some pictures. Thank you for the advice.

Re: 53 F100 Flathead V8 239 not starting help
 

I had a chance to diagnose the issue. When i use the throttle cable from the accelerator I see a thin stream of gas enter the carb. If i hold the accelerator down i can get the truck to start and run, but it stalls out the minute i let off the accelerator. Even with the accelerator to the floor it is not running at max rpms. Any suggestions out there? Fuel pump? Carb issue?

Re: 53 F100 Flathead V8 239 not starting help
 

Sounds to me like it's getting to much fuel, it's flooding.

Re: 53 F100 Flathead V8 239 not starting help
 

What do you think could be the issue for this? It seems to only run when i give it constant gas and quits when I don't

Re: 53 F100 Flathead V8 239 not starting help
 

Opening and closing the throttle doesn't control the fuel flow, it controls the air flow. Fuel is metered in proportion to the amount of air flowing through the carburetor ventures. It appears to only run when the air flow is high enough to match the fuel being supplied. If it is getting to much fuel, it could be the float needle valve sticking open or some internal carb leak.

Re: 53 F100 Flathead V8 239 not starting help
 

Should I try to clean the carb with cleaner first? I did disconnect the fuel line at the carb and it does pump gas when I crank the engine over. Can the jets be clogged? What is the best way to diagnose the problem?

Re: 53 F100 Flathead V8 239 not starting help
 

Rotor Wrench, just wondering what is the airplane in your avatar? Maybe a B-17? I am an old Air Craft mechanic in the USAF

Re: 53 F100 Flathead V8 239 not starting help
 

Have you be running non-eth fuel for 2yrs?

Put a gauge on the pump to see pressure.

Open up the carb and look at it or have someone check it over.

With all that said... might be ignition! ha ha... sorry.

Check pressure or bottle feed the carb to see if it will stay running.

Re: 53 F100 Flathead V8 239 not starting help
 

This happened to me a couple of years ago, check the clips that hold the distributor cap on. One of my clips flipped down causing it to miss.

Re: 53 F100 Flathead V8 239 not starting help
 

I will check the pressure and the dizzy cap. If that does not work, i will get the carb checked out. Thank you

Re: 53 F100 Flathead V8 239 not starting help
 

It's a B-17G. Most would think Boeing but that one was built by Douglas Aircraft at their Long Beach plant.


If it is running lean due to plugged passages or the like, it will run better if you pull out the choke. This cuts the air flow back and gets the mixture back into an operable ratio. Without the choke, it will have a tendency to back fire or hiccup through the throat of the carb. If it is running too rich, the choke won't help at all and it may have a tendency to after fire in the exhaust if too much fuel is leaking by. If you look down the throat into the venturis while it is running, you can see if raw fuel is dribbling down in there. That is if it will stay running while you do that.

Re: 53 F100 Flathead V8 239 not starting help
 

It is definitely running too rich. Choke makes no difference. Plan to get the carb off this week and have it serviced to see if this helps. Does the accelerator lever just pop off of the carb or is there something else to this before I disconnect it?

Re: 53 F100 Flathead V8 239 not starting help
 

Accelerator lever pops off and choke cable needs to be disconnected. A;co vacuum line for distributor. Remove the top of the carb and turn it upside down and slide the float hinge pin out. The needle to the valve should come out and you can check for dirt. The float may have a hole in it too. If you can disconnect the fuel line before the pump and it runs ok for a while then the carb is your problem. I still would not rule out ignition.

Re: 53 F100 Flathead V8 239 not starting help
 

Been busy with work and kids, but got around to working on this. I took the carb off, cleaned all i could with choke cleaner and then used compressed air. Put carb back on and it started right up. The jets in the main body were pretty dirty.

Now when I push the accelerator, it does not return all the way back to idle. I can do this manually under the hood and I can get it to idle, but i have to push the accelerator rod back a little. It was not very smooth when I had it off cleaning it. I assume I am having an issue with the spring lever inside or the accelerator lever itself. Is this rebuildable or should I just buy a new carb?

Re: 53 F100 Flathead V8 239 not starting help
 

If the linkage on yours is like my 50 you can adjust the ball socket out a couple of rounds to use the accelerator pedal return spring to close the carb all the way to the idle screw. I rebuilt mine and had to adjust the rod length after I put the carb back on.

Re: 53 F100 Flathead V8 239 not starting help
 

I tried adjusting, but this did not help. It seems the accelerator lever is sticking. I took the carb back off and will get it looked at. Thanks for the help. I will keep you posted.