Hi there. I'm a bit new on here and have found some great things posted by great folks over the last few months. This is my last resort starting a thread as I am at my end trying to figure this out on my own.
I acquired a 1967 F100 with a 240 straight six 3.9litre a couple months back. I was told (and continue to be told whenever I contact him ) that the engine is in great shape by the previous owner and that it should run very well.
New parts - Coil, Solenoid, starter motor, fuel pump, plugs, distributor, carb, radiator, and all lines and filter.

I'm at the point where I don't know what else to do and cant spend any more time on it without having anything to go on or some positive outlook. I know we have all been there.

Long story shortened: I rebuilt the original autolite 1100 carb and installed it and got the engine running. Yay!!... nope... For 5 straight days for about 4 hours a day I tried to get it to run right. It would sputter on idle but bog and die when throttle was pressed. I tried to do the timing, vaccuum test was good at 20, new plugs, carb taken off and taken apart at least 15 times watching numerous videos from Mike's carburetor and reading threads from Thunderhead on youtube and this forum. Engine still bogged and dies with throttle depressed. Float, idle mixture adjusting, check weights, needle etc... played with over and over.
I decided to give up and get a carter YF carb from amazon. Linkages line up nice (brand new not rebuilt) and easy to install. Only difference was the automatic choke which I ran a metal line to the choke stove location. I was told by the manufacturer that everything is good to go and adjusted and to just slap it on. Everything fit. The engine ran a little better but not smooth and still boggy and stalls when throttle is given.
I discovered that the crankcase was getting fuel in it with the oil. Big issue so I researched and thought it might be the diaphram in the pump leaking gas past down into the oil. I was also told that this could be the reason it was bogging and dieing and not running right. New fuel pump and same old thing and i'm pretty sure I'm still getting some gas in the oil. Oil was changed with new oil and filter. Previous owner is adamant that its not the rings leaking fuel down past the cylinders. Compression is good too.
I took apart the whole exhaust thinking something might be clogged by mice or something right up to the manifold on the block. Clean as whistle now.
I took the fuel tank off and cleaned all the lines and tank.
I tired a little 4-7 psi electric fuel pump out of frustration and the engine actually ran pretty good and responsive to throttle a bit (way smoother than before but still not great) but after further research, I discovered that without an oil pressure switch and mounting the pump near the tank, this can be dangerous. So I would like to stick with the new mechanical pump. Engine runs horrible and bogs and dies.
I sprayed carb cleaner all around the base of the carb and no vaccuum issues.

Can anyone help me. I am at my end.

 

Welcome to FTE.
I guess this truck had been sitting for some time, you did not hear it run or a test drive before you got it to know for sure what the other guy is saying is true or not?

Did you do a compression test or took the owners word the rings & compression is good? Post up the numbers. Also a picture of the plugs.
Do you have a dwell meter / tach and timing light? If not you will need them.
Being it runs with the fuel pump on the motor and you want to use it for safety lets get that hooked back up.
Recheck the firing order 1-5-3-6-2-4
Have you replaced the points & condenser yet? This could be why it will not run and might be a good time to replace them as everything else has been to this point.

When you get it idling again hook up the meter and post up what the dwell is, you will need to look up the spec as I don't know what this is.
Once the dwell is set to spec you can check the timing and set it after the idle speed is set.
As a guess the dwell is off and this will throw off the timing.

Oh that new carb will need to be tweaked to run 100% but should be good enough out of the box to get the motor up to temp before tweaking.
So with the dwell, idle speed, timing set and motor up to temp recheck the idle speed.
With a vacuum gauge hooked up you can adjust the idle mixture screw to get the highest vacuum reading.

That should cover about everything so it should run pretty good and if not let us know what is going on.
Dave ----

 

Once you get it running good, I don't want to add any more changes till it runs good, you may want to check out this post.
https://www.ford-trucks.com/forums/1...x-ignitor.html
Dave ----

 

Thanks so much fuzzface! I'll wait for this rain to stop and follow your directions. I sure appreciate it! Thanks again

 

If it seems to run better with the electric fuel pump then it is more likely a fuel supply issue rather than ignition. Could ultimately be both but it seems to have responded better to fuel. First, there is no assurance that the new pump you bought is a good one, unfortunately. So, you may want to try another from a different source (Napa, for example). Second, there is a chance that your eccentric on the cam is damaged, spinning, etc., or you may have inadvertently installed the actuator arm on the wrong side of the cam so that it is not fully actuating. Sometimes this results in no fuel, other time just a trickle. I found this link which has some suggestions regarding the use of a vacuum pump to check for pinhole leaks in the supply line that will cause improper draw with a mechanical pump. Since you have had so much practice taking the carb off, this time pull the fuel line at the carb and rig up a pressure gauge. Even while cranking you should get 3 to 6 PSI. Also, with a helper, run a hose into a container and ensure that you are getting good flow when you crank the engine.

And, have to ask, how old is the gas in this thing? You had the tank out and cleaned everything up so I'm hoping that it has fresh clean gas.

https://www.cargurus.com/Cars/Discus...13903_ds918960

 

Good luck and keep us posted what you find
Dave ----

 

Update. Sorry for the late reply to everyone. I'm a school teacher that was frantically finishing up this crazy year. So, last night I discovered that the truck won't even start at all now. No spark. What I thought was a fuel delivery problem is now an electrical ignition problem I think.
Took off the 1 and 6 plug and checked for spark. Nothing. Took out a volt meter and have power to coil and distributor cap.
Where can I go from here?
Do you think a faulty distributor was the cause of rough running all along. When the engine idled it was rough to begin with and shook terribly. I thought it was flooding but now I'm wondering if it was a misfire on a few cylinders. (if thats possible) Condensers are super expensive up here (40 bucks and above, crazy I know) I wonder if its better just to order a new HEI distributor? Or can I do anything before that to make sure thats the problem??
Thanks so much for the help!

 

My suggestion is a pertronix points eliminator kit. It won't provide any stronger spark than points in perfect condition, but it will eliminate problems with misadjusted points, fried points, or bad condensers, which seems to be getting pretty common now. It's not a very expensive kit, and you do NOT have to remove the distributor to install it.

 

I agree with the Pertronix but only if you confirm that radial runout is minimal (worn bushings or shaft), that the mechanical advance is functioning (rotates and springs back on its own), and that the vacuum canister and plate are working (pull vacuum - even by mouth - to see that both the canister arm retracts and the plate rotates. If all of those are good, it is a perfect candidate for a Pertronix. If the distributor is shot, I'd vote for a Pertronix distributor that looks like stock before an HEI. It is just a matter of looks for me. If you go HEI there is a big difference in quality between the $79 units and those that run $150 and higher. Do some google searches on the low cost units. Found one where the guy was happy because he bought 2 so he'd have a spare.

 

He's right, I should have mentioned that you need to ensure your current distributor is in good shape.

 

Before jumping to the pertronix points eliminator kit why not check the point?
Pop the cap off and rotor so you can see the points.
You want to turn the motor, by hand if you can, and set the points rub block on a high point of the dist. lobe where they are open.
Now I don't know what the gap should be but after checking to make sure the contacts are in good shape, no high or pits, you can take a match book cover and slip it between the contacts.
It should just drag a little and the 2 contacts should not be pushed open or close when you remove the book cover.

When that done see if you get spark. If not it could be the condenser.
BTW if you put a test light on the neg. side of the coil where the points wire is hooked to, when you crank the motor or open and close (points have to be on a low side of the lob) you should see the light flash and get a spark.
No flash = no spark it is that simple.

And yes if the points were starting to close up, loose screw, that would make it run not so good.
Dave ----

 

One thing that can't be stressed too often is the need to take an incremental, methodical approach to this. Yes of course a good hot spark is crucial, but there's more to it than that. When visiting your doctor, getting a checkup, especially a new patient they want to check everything. Blood pressure, temperature, weight, heart rate, maybe X-rays, the whole 9 yards. When you have a "new" old truck, it pays to check it out thoroughly. Everything - just because the previous owner says it should run great doesn't mean anything. As you discovered. Get yourself a Ford Truck Shop Manual, a compression gauge, mechanic's vacuum gauge, a good DVOM, a test light, and a grease gun. Study 1 chapter at a time and familiarize yourself with what does what, and why.

I've been bending wrenches and breaking stuff since I was a little kid and even routine maintenance jobs, I like to refresh myself with the manual. Ford literally wrote the book on this stuff. I usually learn something I didn't know before. Just because I've been doing something for a long time, doesn't mean I've been doing it correctly. Between the shop manuals, websites, and forums like FTE, has really saved my bacon more than once. Feel a lot more confident tackling stuff.

 

Points are good. I pulled the cap off the distributor and flipped it upside down and no spark to the main electrode when cranking. I just used an insulated screw driver. Good spark from the coil along the wire that leads to the distributor. Cap appears in good condition and I cleaned all the electrodes and not much carbon or anything. Cap isn't cracked or anything. Why would it be getting spark from the coil but not get through a cap?? Its weird.

 

Sometimes there is problem with the center cap contact to the rotor in the cap or the rotor itself may be bad. Lifting the spring contactor on the rotor may help.

If the distributor has turned for some reason the coil may be firing in between two cylinders - either way to far advanced or retarded. Turn the engine by hand and stop where the points just start to open. Look at the position of the rotor and compare it to the posts on the distributor.

 

If you're getting a nice blue spark from the coil wire to ground, though not out to the plugs, then the fault lays either in the cap, rotor, plug wires, or plugs.

Check the carbon button as mentioned. I like to take the wires off (one at a time is probably safest) and polish the brass wire ends shiny bright, and polish the distributor cap receptacles, then spread the connectors out a bit as required, see to it that the wire end terminals are fully seated with a tight interference fit. A smear of dielectric grease on the inside of the boots keeps moisture away. Good solid electrical contact is very important. Kerosene or WD40 is excellent to keep grime and crud off the wires insulation.