Intermitten failure to start.

1969 383 Superbee with MOPAR electronic ignition (distributor &
orange module). Car always started & run perfect all these years.
Restored 6 years ago. Battery perfect and turns over great. When
it first acted up a friend jiggled the wires on the resistor. It
then started up. Put on a new resistor. It ran and started fine for a couple days. Then.....same thing again...no start. Checked
the connections on the resistor. A little loose but tight enough
it should have started. Maybe it's the orange ignition module.
Replaced it. Ran and started fine for a couple days and then again it wouldn't start. When I let off the key from the start
position it "pops" like it wants to start. I tightened up all the
connections going to the resistor but still have the intermittent
won't start problem. Could it be the ignition switch?

More likely than the switch would be the wires at bulkhead connector. They get funky over the years.

Mine acted the same way with the little shudder when you release the key. I found the reluctor to pickup at .024 when it should be at .008 measured with a brass feeler gauge.

What made you suspect the reluctor and how do you correct the
problem? Do I buy a new distributor if the gap is too large?

Jim

take the cap off and check the gap with a brass feeler gauge, if not .008 then loosen the screw on the pickup and set it to the correct gap. btw, even on a new distributor you should still check the gap before installing

If it started after you jiggled the wire, it is possible the wire is broken inside the insulation. If you disconnect the wire from the resistor, and pull on the end, it should pull apart if it's broken inside. I've had that happen to me several times.

Pull the bulkhead connector and check for corrosion. Very common problem on old Mopars. When you move the wires to the resistor it moves the bulkhead wires and gets them to make contact for a while. I believe it is the light blue wire in particular that causes issues.

Went through all the wiring, installed a new ignition switch swapped out coil and ecu. Just found it on a hunch, I had the mopar distributor with the adjustable advance slots so i was in the distributor several times making fine adjustments. I do think the hold down screw for the pickup doesn't hold it tight so I used a star type lock washer under it before cranking it down after the gap was set!

I have the standard Electronic ignition conversion distributor. It has only 2100 miles on it. Same for the brand new wiring
harness & bulkhead. When initially installed, I just dropped it in and it fired up and has run like a million bucks up until
now. Does the distributor I have have the adjustable advance slots and the hold down screw for the pickup. Is this screw
loosened, then the adjustment to .008 made and then tightened?
Do you recommend I take it to the local Dodge dealer to be
checked out since I'm not sure of myself and don't have
access to a brass feeler gauge?

Jim

you would line up the magnet with a tooth then set that gap between the magnet/tooth with a .008" brass feeler gauge (your parts house will have a set of several brass ones one of which is .008". As said clean the bulkhead (metal bristle brush for the male half ones/spare male terminal for the female ones (NAPA 725147 99cents or one from your parts wiring pile}. check your terminals again. pull the yellow wire off of the starter relay to disable the starter & with a helper confirm the coil positive primary and blue/yellow ECU terminals are BOTH getting fire in ign1 ("run", key on) and in ign2 helper holding key to "start" (4) checks

U can set the reluctor gap with a business card...
Just move the pickup in close to the reluctor but not touching, insert the business card to check for adequate clearance, rotate the distributor to make sure everything kleers..

Note that problems can arise when the gap is too wide, and the ECU box will not fire but very few issues when set on the close side..

Also the point of kleening the bulkhead connections is pertinent...
After 40 years the connections get krusty and oxidized.. Pull the connector apart, kleen with a small wire brush, slightly crimp down titer the female tab connector, coat with dia-lectric grease and reconnect...

Just my $0.02...

I just miked (2) business cards, one was 11&1/2 tho and the other was 15 and a half tho ! that is doable cuz the vac adv will open it way farther than that in operation. EDIT I did have that one spark same deal when letting off & it was either the ECU or the ballast I forget which. I was hesitant on posting/suggesting that since he has replaced both (& the prob can be elsewhere)

Is it cranking and not starting, or not cranking at all??

I would agree with this...

but, I was having the same problem plus charging problems on my 67.. NEW everything on car... Turned out to be the battery cable connection on the starter relay was loose.. Not floppy loose, more snug than tight kind of loose... Might check it..

My car was turning over fine but I had no spark and the power cable was getting hot. After swapping everything around I finally changed the starter and that seems to have fixed the problem. Everything on my setup was also new with maybe a few hundred miles on the parts but they are like 10 years old since I don't put a lot of miles on the car. I also had the electrical cutting out and causing the engine to shut off and then would not restart due to no spark. I'm not sure if that was related to the starter or perhaps a lose connection I just happened to fix while swapping parts and testing. Either way see if your battery cable is getting hot it might just be the starter!

It cranks great......just that sometimes, not always it won't start.

I just now checked the gap with a business card as you suggested.
It seemed a little loose but not much. I set it and cleaned the
tip of the rotor. It might take as much as 2 weeks before I know
if the problem is solved as most of the time it has been starting but not always. As for the wiring and bulkhead.....they
are all brand new. I installed all new when I restored the car.
I only have 2100 miles on the restoration, so the bulkhead should
be good.

Jim

Check to make sure the orange box has a good ground thru the paint... That one bit me once in the beginning as I didn't want to scratch off the new paint...

hi
check the wire plugs at base of stering colom,

clean the plugs with elictrical cleaner and make sure they plug together correctly .

The times it cranks great but won't start do you know if it's getting any spark? Mine would do that. It cranked fine and would not start and I would check and have no spark but I would try again and it would have spark and then suddenly no spark again. It was very frustrating. It seems the starter going bad was pulling so much power from the battery that there wasn't enough power left to create a consitant spark to fire the coil.

When it does start does it die suddenly?

Like others have said, check that the ECU is grounded and check for loose contacts.

Sounds like you, my friend, have a dizzy issue. My car did exactly the same thing.

Read this:

https://board.moparts.org/ubbthreads/ubbthreads.php/topics/1861900/re-no-spark.html#Post1861888

No, after it starts it runs great continuously. How do you know if the starter is the problem? I checked the ground at the ECU.
The last time it wouldn't start I added an extra ground. It still
wouldn't start.

The difference here is that yours would shut down after running
for a while. Mine runs continuously once and if it starts
whether it's hot or cold

If it won't CRANK - it's a starter issue. From your original description people could not tell if it would not crank, or if you had a no spark condition. It sounds like you have an intermittent no spark condition. With the key in the START position you bypass the ballast resistor and crank the starter - full 12 volts to the coil. When you release the key it returns to the RUN position and the juice to the coil is reduced by the ballast down to 9 volts. I would put the key in the RUN position )don't crank the motor) and check the voltage with a voltmeter first at the coil and then back at the ballast. The re-check the voltage while jiggling the wires going to the coil and then to the ballast - see if the voltage goes to zero - if so, loose connection somewhere or a break in the wire. Check the ground too on the ECU - the factory used a self tapping bolt with a star washer like the ones on the starter relay to cut into the steel body of the ECU. If all that is good check the gap at the reluctor in the distributor - .006 - .008. The DC distributor, if it's the older style, is really a factory distributor and will have the set screw and adjustment slot. If all that fails replace the pickup in the distributor - the thing you set the gap on.

I've come across this twice this year.My 70 Chrysler 300 with a old MP conversion kit...every so often it would not start but would kick when i released the key.Changed nearly everything...still did it.Finally took the P4120505 control box and swapped it with a crusty used blue box...been mint ever since.Customer towed in his big block Charger a couple of weeks ago with the same problem.Put a new Chinese control box on and no issues since.20 or 25 years ago the orange boxes had a similar issue...run fine till they warmed up and then would quit
until they cooled down.

I put a new ECU control box on and it still would not start. It
never quits. If it gets started it runs like a new car even all
warmed up.

It cranks great....just that sometimes (not always) it won't
start. Your idea is a new one. One that no one has suggested and
one I need to try the next time it won't start.

Next time it won't start, immediately disconnect the distributor connector and measure the resistance across the two contacts of the distributor plug.

If it's over 1000 ohms, you'll have likely found your problem.

What's a distributor connector? Can you describe the 2 contacts
of the distributor plug?

its the pigtail coming out of the side of the dist (has 2 wires and a zigzag pull apart connector). You would ohm the metal male tip and the recessed female terminal on the dist half of that connector

My problem was identical to yours. Too wide a gap at the reluctor. Thanks to your help I discovered the problem. Many....
many thanks for your input and thanks to everybody else that made
suggestions. All you guys are super!

Jim

Glad I could help, I know how frustrating it is!! Mike