Chipper's Ford 300 inline 6, sudden no-start

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This is from his OP
"Compression: I tested each cylinder and got the below PSI values
120, 100, 125, 120, 125, 125 all these are good enough to support combustion, right ?"
yeah and? one cylinder being goofy isn't unheard of, and 100psi on an industrial engine isn't the end of the world, seen em run at 60psi, it could be a clue to something else, but its not exactly a high performance engine is it? its a ford industrial built to survive nuclear holocaust, locusts, and rivers running red.
$$ says its just dead plugs, or maybe the timing slipped.
 
As a mechanic, I've grown to hate anything with magic boxes attached to it. Great when they're working ... but when they're not they make you want to set the engine ablaze, then smash it with a sledgehammer. Expensive and failure prone to replace, and infuriating to troubleshoot. I'd get rid of that and install something simple like Mad Professor suggested.

But before we go too crazy, did you try shooting some brake clean down the carb and see if it'll run, or at least pop a few times? If it fires, you've got good spark, timing, and compression, but have a fuel issue.
 
Is the distributor vac advance stuck full advance?, broken spring, is its shaft, gear or cam gear broken? Is it turning over rapidly when attempting to start- low compression requires a fast starter, did you check timing with a timing light while cranking, is it consistent every rotation? if it is try some plugs/rotor button and cap if the originals are all wet, pull valve cover and inspection plates to check push rods and valve lash, rotate by hand and feel each cylinders compression stroke, did any seem to be flat or too easy? did you pull the fuel supply line and check fuel delivery volume while cranking?
#3 is closer to the carb and should get fuel quickly but all 6 should puff atomized fuel after 6-8 seconds or cranking. look where I circled for wire burn through causing grounding
https://prnt.sc/XVcMCTKA3Js5
 
It was running but suddenly stopped.

We put in 6 new plugs but still no-start, no change, all plugs spark.

We put in a new ignition module, no-start, no change, all plugs spark.

We took out all 6 plugs and checked each for visible spark, all have visible spark, pass.

With distributor open, rotor at cyl 1 position, piston #1 (and 6) is at top , timing notch on crank pulley is positioned next to timing marks on engine block. I think I have a timing light somewhere, hopefully can find it and check timing.

When engine turns over distributor rotor turns.

With all plugs out, gasoline spits out of cylinder 3 ! All other cylinders appear dry. WTF! How is this possible with a functioning cam and compression reading on all cylinders?

Taking it to the mechanic who we bought it from this weekend. I hope he finds the problem, even if it makes me feel stupid !
.
 
You can crank it over with the valve cover off, if the lobes of the camshaft are wiped ,timing will be fine and the rotor will turn in the dizzy.
I remember the rockers on some of the fords being adjustable? Have you adjusted them? Or are they stamped steel.
 
If you have spark, compression and your dumping fuel in it it has to be a timing issue or weak spark. Check it with a timing light if it’s good then by pass the voltage regulater and see if it fires.
Are the plugs wet after you try starting it?
 
Didn’t see your last post. You will still have compression if the valves aren’t moving. Although Iv never seen a 300 wear a cam off. Enough to do so.

Did it run fine before it quit? Sounds like there’s something in the intake blocking off all other cylinders or only number three is breathing for some reason. Deffinety strange
 
So many good comments and suggestions, thank you everyone! The saga continues.

Today I’ll remove the valve cover and verify the cam is moving. If cam wasn’t moving, would the distributor be turning? (It is) or would I read 120psi compression in ALL cylinders? (I do)

Spraying starting fluid into the intake manifold should bypass any fuel pump or carburetor issues and at least produce a cough or pop or wisp of white smoke , I get none of these.

Will also try the timing light check, if I can find my timing light.

—-Possible Scenario To Explain This—-
If the fuel is contaminated with water then the plugs all become so wet with bad gas that they don’t spark and the water contaminated gas doesn’t burn . But when removed from cylinder, all plugs produce spark. Also , if plugs are wet with bad fuel, even the starting fluid won’t ignite.

Although the gas from top of tank looks clear , I’d better drain the entire tank and start with fresh fuel .
 
So many good comments and suggestions, thank you everyone! The saga continues.

Today I’ll remove the valve cover and verify the cam is moving. If cam wasn’t moving, would the distributor be turning? (It is) or would I read 120psi compression in ALL cylinders? (I do)

Spraying starting fluid into the intake manifold should bypass any fuel pump or carburetor issues and at least produce a cough or pop or wisp of white smoke , I get none of these.

Will also try the timing light check, if I can find my timing light.

—-Possible Scenario To Explain This—-
If the fuel is contaminated with water then the plugs all become so wet with bad gas that they don’t spark and the water contaminated gas doesn’t burn . But when removed from cylinder, all plugs produce spark. Also , if plugs are wet with bad fuel, even the starting fluid won’t ignite.

Although the gas from top of tank looks clear , I’d better drain the entire tank and start with fresh fuel .
Never had the ford I-6 apart but most older auto distributor and oil pumps run off the camshaft.
 
After you have tried to start the motor and sprayed "STUFF" in the intake, you nave p'bly washed all the oil off of the rings, That might explain low compression and the #3 &4 cylinders are centered under the carb so they will be wet when 1-2-5-6 are dry(er). I would be marking the crank pulley/Timing mark, , check position of the the rocker arms for top dead center then rotor position of distributor to verify timing is where it should be. Timing gears are still sold because they wear and do jump timing. Normal to jump time and backfire when you are trying to start it but not unusual to jump more than 1 tooth and get spark just not at the right time/timing. A good Mechanic that is old enough to remember these could be a real help.
EDIT: I missed post #31 OOPS Are the rocker arms loose on 1 & 6 as well? To verify the cam is in time also.
 
After you have tried to start the motor and sprayed "STUFF" in the intake, you nave p'bly washed all the oil off of the rings, That might explain low compression and the #3 &4 cylinders are centered under the carb so they will be wet when 1-2-5-6 are dry(er). I would be marking the crank pulley/Timing mark, , check position of the the rocker arms for top dead center then rotor position of distributor to verify timing is where it should be. Timing gears are still sold because they wear and do jump timing. Normal to jump time and backfire when you are trying to start it but not unusual to jump more than 1 tooth and get spark just not at the right time/timing. A good Mechanic that is old enough to remember these could be a real help.
EDIT: I missed post #31 OOPS Are the rocker arms loose on 1 & 6 as well? To verify the cam is in time also.
For any more details I would have to rely on my Mechanic brother (I often do) Good luck.
 
I have a JLG boom lift with the Ford inline 4 cylinder industrial motor , actually the same motor that was in the Ford pinto back in the early 80’s. Same situation, went through everything you had tested pull off the timing cover and timing belt jumped 2 teeth , replaced the belt and water pump while I was in there. Started on less than 2 revolutions and it’s running better now than it ever did.
 

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