K301 Suddenly Died, No Start, No Spark (‘68 Charger 12)

[BrianKoch 354]

Gentlemen,

 

I am in need of help. While doing yard work with my K301 powered ‘68 Charger 12 it suddenly came to a stop and won’t start again. 

My troubleshooting so far: 

 

Fuel:

• stabil/87 and clean

• good flow before and after pump

• carb clean, recently rebuilt, float level correctly set 

 

Compression:

•good? - blows finger off spark plug hole

•good turnover but doesn’t fire off

•piston and cylinders move freely
•valve lash set .008 intake .018 exhaust
•breather assembly correct and recently serviced with new gaskets and filter
•head gasket not broken, head bolts tight, some carbon on head

 

Spark:

•no spark
•all electrical/ignition components were replaced 1 year ago except voltage regulator
•no loose connections, no grounding connections

•inspected and applied graphite to starter shaft

•changed plug
•12v to coil good
•cleaned points, points wire has continuity

•condenser ground good

•swapped battery, points and wire, plug and wire, coil, and condenser from running K301 (‘69 Charger 12)
•points push rod does push out when turning engine over by hand, but unable to get points timed using multimeter method and timing mark on flywheel

 

What else should I check/do?

 

Edited April 12, 2024 by BrianKoch

[OutdoorEnvy 1,763]

Does the engine turnover when you try to start it?  Assuming it does I would clean up the grounds as that is quick and free.  Also test all parts, even though you replaced them they can go bad.  Do you see spark at the points when you turn the engine over?  If not start there and to next component and test, etc.  If you have a different set of points I would try that too.  I had a new set that didn't work so am still using the old set 4 years later...

[wallfish 17,843]

Sure sounds like you have the bases covered.

Could the coil be loosing 12v power when the key is turned to start? Like bad key switch contacts.

An intermittent problem somewhere?

 

For spark testing purposes, sometimes this can be helpful for hunting down a problem

With the engine rotated so the points are closed, key to run. You can manually flip the points open with a screwdriver to simulate it turning over and more easily watch for spark and test the wires as you do it.

[pfrederi 18,552]

If yo have a test lamp. put it on the - coil terminal and crank the engine should flash on off if the points are actually working.

[953 nut 59,212]

Remove the wire from your condenser to the coil/points. If you condenser has shorted out this should restore spark from the coil. 

[ranger 1,790]

You could try a temporary lead from the + battery terminal to the + terminal on the coil, and then try to start the engine. Don’t connect permanently, use an alligator type clip to connect to the battery. If it starts then work your way back through the wiring, etc. You may see battery voltage at the coil when testing, if the points are open and you have a poor connection, (high resistance etc somewhere), but as soon as the points close and the coil ‘loads’ the circuit, this ‘voltage’ will disappear. 

[Ed Kennell 41,312]

2 hours ago, wallfish said:

Could the coil be loosing 12v power when the key is turned to start?

Make sure you have 12v at the + coil in run and start ignition switch positions.

Then I usually replace ignition components with those from a good running engine.     I start with condensor, spark plug, spark plug wire, coil, and points.

[wallfish 17,843]

1 hour ago, Ed Kennell said:

   I start with condensor, spark plug, spark plug wire, coil, and points.

Supposedly already did that which is why this one is a tough one to internet diagnose

Edited April 12, 2024 by wallfish

[BrianKoch 354]

Update: when cranking, voltage drops to 10.8ish on coil (reminder this coil is from my other running k301)

Edited April 12, 2024 by BrianKoch

[kpinnc 14,258]

11 minutes ago, BrianKoch said:

Update: when cranking, voltage drops to 10.8ish on coil (reminder this coil is from my other running k301)

 

That's normal. The starter eats quite a bit of power overcoming engine compression. The coil only needs 6V to build spark. 

 

Sounds like all good so far. 

[oliver2-44 10,567]

4 hours ago, ranger said:

You could try a temporary lead from the + battery terminal to the + terminal on the coil, and then try to start the engine. Don’t connect permanently, use an alligator type clip to connect to the battery. If it starts then work your way back through the wiring, etc. You may see battery voltage at the coil when testing, if the points are open and you have a poor connection, (high resistance etc somewhere), but as soon as the points close and the coil ‘loads’ the circuit, this ‘voltage’ will disappear. 

Definitely try this.  

But don't leave it connected when not cranking or running.  It can overheat and burn up a coil if left connected.  A couple (3 - 5) minutes at a time is fine..

[BrianKoch 354]

Update:

•running now, but can’t explain why

…oh well, until it breaks again

 

thank you, gentlemen! 

 

Edited April 13, 2024 by BrianKoch

[ranger 1,790]

If you disconnect the neg lead from the coil to the points, attach a short lead to the coil neg connection, power the coil on, and with the spark plug out and grounded, flash the neg lead on and off the engine block, or battery neg terminal. If you then have a spark it points toward a points or points wiring fault. When you mentioned not being able to set the points via the timing mark, have you checked to make sure the flywheel key hasn’t sheared?

[BrianKoch 354]

1 hour ago, ranger said:

If you disconnect the neg lead from the coil to the points, attach a short lead to the coil neg connection, power the coil on, and with the spark plug out and grounded, flash the neg lead on and off the engine block, or battery neg terminal. If you then have a spark it points toward a points or points wiring fault. When you mentioned not being able to set the points via the timing mark, have you checked to make sure the flywheel key hasn’t sheared?

I’d like to check the flywheel key next because it is running rough and backfired through the carb when shut down so that would mean timing is advanced right plus I still can’t time it with multimeter off timing marks. 
 

Any recommendations on a flywheel puller?

 

Not having luck with dead blow hammer and prybar.

 

Here’s a photo of flywheel and crank. That’s copper anti-seize, not rust, as I did have flywheel off last year when working in a shop and had access to a puller from a coworker mechanic. I think we may have replaced the key at that time, but can’t recall…

 

Edited April 13, 2024 by BrianKoch

[pfrederi 18,552]

The key looks ok

 

[953 nut 59,212]

Backfiring on shutdown shouldn't be an ignition issue as the ignition is OFF. Could be a carbon buildup that is holding heat. 

1 hour ago, BrianKoch said:

dead blow hammer and prybar.

Use a harmonic balancer puller.     most auto parts stores have tool loan programs so you don't need to buy one.

[BrianKoch 354]

Update: 

Bought a $10 harmonic balance puller from Napa and popped the flywheel off. Key looks good to me. 

[Ed Kennell 41,312]

Can you position the piston  at TDC thru the spark plug hole or by removing the head.   Then verify the points are opening at the proper time?

[pfrederi 18,552]

Did you ever try the test lamp coil - (points side) and see if it flashes if it doesn't there is problem with the points (contacts or insufficient movement).  When you say you couldn't time it what happened?  What is current gap setting

[BrianKoch 354]

Update:

Discovered I incorrectly set valve lash out in the field (where I broke down) while troubleshooting. I set TDC by aligning the T on flywheel with timing mark, but must have been on the wrong stroke. This resulted in poor engine performance and a backfire through carb when it ran enough to move into the garage. 

 

Yes, I was able to confirm the new points are good and functioning via test light flashing on and off. However, I only was able set them with a feeler gauge to 0.02 at TDC and still can’t time via multi meter method. 
 

Now that valve lash is correctly set and new points are installed it’s running pretty well. I do notice a small continuous arc at the points. Could this be caused by the timing not being 100% correct or something else?

Edited April 15, 2024 by BrianKoch

[ranger 1,790]

Turn the engine over by hand, (with the plug lead disconnected). When the points are at maximum gap, then set to 0.020”. Then with test light , or multimeter connected, digital meters need to be on ‘diode/continuity’ mode for this test, resistance mode won’t work! Turn engine back past t.d.c then forward until light goes out, or meter shows open circuit! 0.020” at t.d.c, may or may not be absolutely correct, I don’t know? Points should begin to open as your timing marks align. 

[953 nut 59,212]

I prefer a test light rather than a meter for static timing, faster response time in my opinion.

[ranger 1,790]

9 hours ago, 953 nut said:

I prefer a test light rather than a meter for static timing, faster response time in my opinion.

Plus it’s easier to see a light going out in your peripheral vision, whilst staring directly at the timing marks, than it is to see a multimeter’s display change!