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

[pondnstream]

Hi

I am really stumped because I cant figure out why this Ford CSG-946p-300 inline 6 engine suddenly wont start .
It was running along just fine and then died.
Everything checks out fine , I can't find any trouble , except of course that it wont start or even fire once.

Ignition - tests pass. It has solid state ignition, no points.
Using a neon clamp-on test light on both the coil-to-distributor wire and to each spark-plug I get a healthy spark in the neon tester.
Removing the sparkplugs and grounding them against the block, I see healthy spark.

Ignition Timing - I checked the firing order and the plug wires, these are correct. The distributor base is tight and couldn't have moved.

Valve Timing - the engine has cast iron cam gears so I doubt if the valve timing could be off, also the distributor rotor turns and is gear driven by the camshaft.

Fuel System - I spray starter fluid i, nto the air intake, result: no pop or fire, nothing. Squirt raw gasoline into the intake manifold below the carburetor, result: nothing, no start, no pop . Fuel tank is half full.

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 ?

Any suggestions , what am I missing ??

 

[9050lx]

WHich ignition? TFI module?

 

[pondnstream]

I’m not sure which module I have , I took several pictures but there are no markings i cold see. The small box in the picture, is the voltage regulator and that is a Motorola 8RH2002

 

[9050lx]

What year is it? vacuum advance distributor?

 

[pondnstream]

Yes , the distributor has a vacuum advance on the side. The engine is probably from 1980’s .

 

[9050lx]

The old Ford early 80's "brain ignition modules were not necessarily durable.They were in size around a 6inch square box by 2inches thick with a heatsink built into the external box. If that is what you have you could wire a MSD 6 ignition CDI unit or something similar to bypass it.Is the coil output a blue spark or orange?May just be a coil.To find the ignition box,you may be able to trace back from the hall effect pickup in the distributor.Edit" Not positive which ignition you have, I guessed the "Duraspark" ignition.Edit2: Sometimes they will run when cooled off.

 

[pondnstream]

I think what you described is the ignition module I have a aluminum box with absolutely no name or brand marking.

Are these modules obsolete or can I plug in a similar replacement or is that what you mean as bypass it?

I’ll have to check on the spark color at the coil. The spark at the plug was bright white , almost the brightest spark I’ve seen at a spark plug, which made me question how in the heck it could NOT be firing.

This is definitely not running when cool.

 

[9050lx]

That is a duraspark box. In my recollection the OEM Ford ones were the longest lasting.I remember replacing with part store units that would not last very long. If you have a good spark however I am not sure if that is your problem. If you do go with an MSD 6 box, they have 2 trigger wires to the distributor,a negative,a positive, and the coil wires, very simple and probably more durable than a part store duraspark box.Some of your wires in there looked iffy,I would check there first, maybe even the ignition switch.

 

[pondnstream]

Following your remarks, I looked up Duraspark and they are identified by the color of the plastic “grommet” . So I have a DuraSpark Blue Grommet. I believe a DuraLast F102 is a equivalent replacement

Color	Year(s) Used	OEM no.	Description
Black grommet	1974	DY157
Green grommet	1975	DY166
Blue grommet	1976–87	DY184	49-state

 

[POGuy]

Following your remarks, I looked up Duraspark and they are identified by the color of the plastic “grommet” . So I have a DuraSpark Blue Grommet. I believe a DuraLast F102 is a equivalent replacement

Color	Year(s) Used	OEM no.	Description
Black grommet	1974	DY157
Green grommet	1975	DY166
Blue grommet	1976–87	DY184	49-state

Any safety interlock switches causing a no-start condition?

 

[9050lx]

Good question.check wiring carefully

 

[pondnstream]

Update
- Installed a new ignition module: DuraLast blue grommet
-removed all spark plugs and checked for a healthy & visible spark on each plug, pass, all are good
- checked that distributor rotor is at cyl #1 when cylinder #1 is at TDC
ODD Observation: with all plugs out and cranking engine for spark tests , gas mist and droplets shoot out of cylinder #3 but only cylinder #3, all other cylinders appear dry. This seems to be a clue to something like valves stuck but compression tests in all cylinders shows 100 psi +, how could I get all cylinders w compression if valve or cam was not working?

 

[KonaMauka]

Maybe try pulling valve cover and cam cover to inspect. Parts do break, but you would think it would still run, just poorly.

 

[Aknutter]

Show us a clearer picture of the instrument cluster, ie guages and start button

 

[Aknutter]

Let's treat it like a chainsaw.
Air fuel spark

Weak coil?
Has spark but not under compression?

Do these motor/power units use the Ford infamous fusible link ?
Bad ignition switch?
Wiring on ignition switch?

Try bumping/ jumping the stater solenoid to start with key in run position.

 

[lone wolf]

Update
- Installed a new ignition module: DuraLast blue grommet
-removed all spark plugs and checked for a healthy & visible spark on each plug, pass, all are good
- checked that distributor rotor is at cyl #1 when cylinder #1 is at TDC
ODD Observation: with all plugs out and cranking engine for spark tests , gas mist and droplets shoot out of cylinder #3 but only cylinder #3, all other cylinders appear dry. This seems to be a clue to something like valves stuck but compression tests in all cylinders shows 100 psi +, how could I get all cylinders w compression if valve or cam was not working?

100 range is pretty low , also have you looked to see if the fuel has water in it?

 

[northmanlogging]

100psi on a 300-6 is fine, 120-130 would be better but it will run on 100psi
Change your spark plugs, you may have spark but not under compression, or it could be showing spark with a testor but not getting any through the plugs.
But first, does it have gas in it?

 

[northmanlogging]

as for safety switchs, fuseable links ignition etc etc... if he's tested spark and shown to have spark, its clearly none of those things. So its either bad plugs, weak coil or bad/no fuel, though he did mention it wouldn't pop on ether... so I'm guessing plugs/coil or maybe cap and rotor

 

[lone wolf]

as for safety switchs, fuseable links ignition etc etc... if he's tested spark and shown to have spark, its clearly none of those things. So its either bad plugs, weak coil or bad/no fuel, though he did mention it wouldn't pop on ether... so I'm guessing plugs/coil or maybe cap and rotor

100psi on a 300-6 is fine, 120-130 would be better but it will run on 100psi
Change your spark plugs, you may have spark but not under compression, or it could be showing spark with a testor but not getting any through the plugs.
But first, does it have gas in it?

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 ?"

 

[9050lx]

Throw a timing light on that thing.Please check the ignition switch, coil leads, distributor leads,does it have a ballast resistor? I would as well check the fuel pump and filter.