72 F250 360 fuel/ignition issue - need advice

[mfdengineer]

I have been working on a 72 F250 and would appreciate any input. Truck sat for several years without use. Just the other day I was installing the new brake booster and master cylinder so I thought I would let it run. Cranked fine and idled fine so I thought I would get a clip of it running. While it was running, it all of a sudden started missing and quit. Now it won't run without giving it quite a bit of fuel and then it runs horribly. I'm thinking it might be a bad condensor but it is brand new. I plan on testing it with a meter but I would certainly appreciate any feedback.

Verified fuel pump is working by cracking the fuel line to carb, plenty of fuel when starting. Removed the hat on the carb and the bowl is full of fuel. Carb is squirting fuel in both barrels when pumping accelerator pedal. Carb appears to be fine.

All of this was done and engine was running fine up until what you see in the video.
-New cap and rotor
-New points
-New plug wires
-New spark plugs
-New coil
-Carb rebuilt
-In-line filter at fuel pump

Running video clip: https://streamable.com/r564nm

[sparky72]

I would pull some plugs and see what they look like first. From the video it looks like you might be burning quite a bit of oil and your plugs may be fouled, causing the miss and hard starting.

Also, when you say "inline fuel filter at pump," is that inline filter between the tank and pump, or between the pump and carb?

[mfdengineer]

I will pull all eight and inspect them. It was burning oil 20 years ago when it was being driven so I'm sure it is in need of a rebuild.

There's actually two. One between the tank and fuel pump, then one inside the fuel pump.

I was running it off of a gas can initially until I got the tank removed and cleaned. It was not bad but did need some cleaning. I put the tank back in and it ran fine off the tank after that.

[sparky72]

Reason I ask is that I believe generally it's not recommended to have a filter between the tank and pump on vehicles like these as they can cause the pump to have issues pulling a sufficient volume of fuel from the tank. Many people use them the way you described, however, so it may not be an issue. Worth swapping the filter out to see if that helps, though.

[mfdengineer]

I looked over the fuel lines and found the rubber line that connects the hard line from the tank to the hard line that runs along the frame to pump was severely cracked. I replaced it with a new piece of hose and will test it later this week. I worked on tearing down the front brakes and did not get a chance to crank the truck. I will let you all know. Thanks for the comments, they are much appreciated.

[jimmy828]

I looked over the fuel lines and found the rubber line that connects the hard line from the tank to the hard line that runs along the frame to pump was severely cracked. I replaced it with a new piece of hose and will test it later this week. I worked on tearing down the front brakes and did not get a chance to crank the truck. I will let you all know. Thanks for the comments, they are much appreciated.

Fuel pump sucking air with that crack. Not good.

[mfdengineer]

So the new fuel line didn't change anything. It tries to start, it'll hit a few times then nothing. Then it will hit a few times and over and over. It's getting plenty of fuel to the bowl so I'm at a loss. I'm thinking about tearing the carb down again. I did notice that the passenger side of the carb is wet, fuel I suppose.

It's so crazy how it was running and now it's just almost dead.
Any suggestions??

[jimmy828]

have you tried pouring gas down the throat of carb or spray starting fluid in carb to see how it reacts?

[Jsimon]

Are you able to do a compression check or pull valve covers? Reason I ask is you say the engine sat for a few years. If a valve is sticking it can bend the pushrod. Same thing happened to mine.

[sparky72]

I am not surprised it’s not wanting to run based on that spark plug picture Clean that carbon off or put in some new plugs. How many miles/hours of run time are on those plugs?

[mfdengineer]

There's not any miles on those plugs because I've been working on getting it driveable. I put them in when I first started working on the engine last fall. There was quite a bit of oil in each cylinder from getting it to turn over freely. I did clean the plugs today and checked compression. I spent most of the day putting the front drum brakes back together and greasing the wheel bearings so I didn't get to spend much time on the engine. Here's what I've done.

-Disassembled the carb and cleaned again. Did not notice any debris or obstructions.
-Verified 12v at solenoid, ignition post with switch on, and 12v at coil.
-Verified connections on distributor and coil.
-Tested starting with 2 different known good coils with no change.
-Compression driver side grill to firewall 100, 120, 85, 105
-Compression pass side grill to firewall 120, 110, 90, 110

Now truck doesn't fire at all. I am going to try a new condenser and see what happens. I plan on getting a spark tester to see what each plug wire is getting.

Passenger side