Is this distributor pickup destroyed and what could have caused issues?

[DartThis74]

Hello All,

Long story short, I have finally got around to get my '74 Dart Sport 360 back up and running to an extent. The last time I drove it (2022) and parked it in the garage I had a heck of a time keeping the engine going while driving it as it was severely hesitating, stumbling and fall on its face, especially during acceleration. Thinking it was really a carburetor problem (due to not driving it often and possibly bad gas), I got the carburetor tuned up off engine and I'm still seeing and feeling the motor acting like it is misfiring or doing weird things. I pulled the distributor cap off and low and behold it is a mess under the cap. No Earthly idea how, but the rotor contact spring was bent out of shape, hardly touching the button on the cap, blade is severely fouled (had heavy deposit of metal on the tip), the contacts on the cap are really fouled and corroded. Okay simple enough I can replace these easily, BUT my main concern is the ignition pickup. Looking at videos online and pictures of replacement parts these all look to have the magnet sticking out off the coil. Mine on the other hand looks very flat against the coil. I can't honestly say the reluctor looks damaged as if it hit the pickup and sheared it off, because it don't see significant damage to it. The ignition pickup assembly is tightened down and not loose to where it could have slipped into the path of the reluctor.

1. Judging by the pictures can you determine if indeed this pickup looks damaged, should it be replaced ?
2. What could have really caused the rotor to be so damaged and bent ?
3. If rotor was damaged on the spring it would have caused such significant fouling ?

Image taken from Youtube video showing the pickup sticking out...

 

[Dana67Dart]

Check for up and down movement of the shaft the rotor rides on

 

[4spdragtop]

Looks like the shafts bearings are pooched. The pickup as well.

 

[Mopar head]

First I`ve seen a mangled rotor like that.
Did you install a new advance can?

 

[DartThis74]

First I`ve seen a mangled rotor like that.
Did you install a new advance can?

I have not put a new advance cannister on this distributor.

 

[DartThis74]

Looks like the shafts bearings are pooched. The pickup as well.

If this were the case, I should be able to see a sloppy tolerance in the shaft play if I tried to jostle it around right ? I try moving the shaft and it is very ridged for the most part, has a very very slight tolerance of play. So if the shaft barely moves the reluctor doesn't seem to have any damage to it, I'm so confused how this pickup looks the way it does when compared to other images i see online of a replacement part.

 

[DartThis74]

Check for up and down movement of the shaft the rotor rides on

How much can it move within an acceptable tolerance? I see that I can pull up on the shaft about 2.5-3mm

 

[4spdragtop]

If no movement the shaft is probably good. But ive been down this road before with "new" pickups. If it has vac advance, apply a vacuum(Mighty Vac) to the canister while setting the proper gap. I think its .008"?

If this were the case, I should be able to see a sloppy tolerance in the shaft play if I tried to jostle it around right ? I try moving the shaft and it is very ridged for the most part, has a very very slight tolerance of play. So if the shaft barely moves the reluctor doesn't seem to have any damage to it, I'm so confused how this pickup looks the way it does when compared to other images i see online of a replacement part.

 

[Dana67Dart]

How much can it move within an acceptable tolerance? I see that I can pull up on the shaft about 2.5-3mm

That's probably fine I had one with over 1/4" is why I asked

 

[Dicer]

Mismatched cap and rotor or initial installment issues.

 

[Mopar head]

I have not put a new advance cannister on this distributor.

I asked because I had a distributor on the bench and was applying vac. to it and noticed that the pickup moved closer to the reluctor. That worried me to not even run vac. advance, seeming it would crash, something you may want to test too.

 

[RustyRatRod]

Mismatched cap and rotor or initial installment issues.

This ^^^^ is what I suspect and where I would start.

 

[DartThis74]

I asked because I had a distributor on the bench and was applying vac. to it and noticed that the pickup moved closer to the reluctor. That worried me to not even run vac. advance, seeming it would crash, something you may want to test too.

Interestingly enough I just tested the vacuum canister and it seems like the diaphragm is broken because there is zero restriction when sucking on it. Guess I need to replace that now...

 

[DFX 340 Duster]

To answer your first question, yes, I believe the pickup is damaged and should be replaced. As for the cause, take note of Rusty’s comment. Finally measure the shaft play per the service manual.
Of course, you could pull the distributor and send it to @halifaxhops for evaluation and refurbishment.

 

[toolmanmike]

She ate her pigs.

 

[George Jets]

Put in a new Rotor, and new or good used electronic pickup.

Gap the Pickup to the Reluctor at .08 ths.

☆☆☆☆☆

 

[Professor Fate]

The vac can is toast, the pickup is shot, you need a cap & rotor, and you've got endplay so the bearings are an unknown at this point...
Don't bother throwing parts at it, either have @halifaxhops rebuild the whole thing if you need/want to keep it numbers matching; or just throw a new distributor in it from NAPA, O'Reilleys, or even RockAuto (at under $60 complete, you can't even buy the parts you're gonna need for that). Some will talk down the replacement distributors, but if all you want to do is get it running and driving with minimal hassle it's the way to go.

 

[RustyRatRod]

She ate her pigs.

I love some good bacon.

 

[Bewy]

I see NOTHING wrong with the pick up & no need to replace unless it measures outside the 140-400 ohm range. You can easily check it on the car. Remove the coil lead from the dist cap & place it 1/4" from a ground source. Connect the pick up, turn on ign, & spin dist shaft. If ok, you will get a spark.
Sometimes the p/up coil is close to the p/up tip. That is ok & does not cause a problem. If the p/up coil is a bit loose, you can push it back & secure it with a blob of silicon.

 

[Killer6]

I see NOTHING wrong with the pick up & no need to replace unless it measures outside the 140-400 ohm range. You can easily check it on the car. Remove the coil lead from the dist cap & place it 1/4" from a ground source. Connect the pick up, turn on ign, & spin dist shaft. If ok, you will get a spark.
Sometimes the p/up coil is close to the p/up tip. That is ok & does not cause a problem. If the p/up coil is a bit loose, you can push it back & secure it with a blob of silicon.

His pickup is toast, re-read the post, OP posted a pic of a normal one.

 

[Killer6]

Interestingly enough I just tested the vacuum canister and it seems like the diaphragm is broken because there is zero restriction when sucking on it. Guess I need to replace that now...

If that rotor tang got bent, the spark from the coil probably went to the reluctor wheel & started jumping to the pickup core, I'd replace cap, rotor & pickup coil. Be sure to set the gap w/brass feeler gauge, and do it removed from the engine, making sure the advance plate is seated before setting & after installation in the engine. When set correctly (check all 6 reluctor teeth, loading the shaft slightly towards the pickup), You should feel a pronounced magnetic bump in Your fingertips every time a tooth passes the core, & giving it a twirl should produce a low buzzing noise even tho' they are not making contact.

 

[RustyRatRod]

If that rotor tang got bent, the spark from the coil probably went to the reluctor wheel & started jumping to the pickup core, I'd replace cap, rotor & pickup coil. Be sure to set the gap w/brass feeler gauge, and do it removed from the engine, making sure the advance plate is seated before setting & after installation in the engine. When set correctly (check all 6 reluctor teeth, loading the shaft slightly towards the pickup), You should feel a pronounced magnetic bump in Your fingertips every time a tooth passes the core, & giving it a twirl should produce a low buzzing noise even tho' they are not making contact.

I just fold up a piece of printer paper. Tween .006-.008. Just right.

 

[Killer6]

Interestingly enough I just tested the vacuum canister and it seems like the diaphragm is broken because there is zero restriction when sucking on it. Guess I need to replace that now...

Yes, and a couple more notes, make sure the arm on the vac can doesn't lift or twist the advance plate when installed, I've seen them twisted or clocked off,......and whether You use brass or folded printer paper, the magnetic field will pull the core to the tooth when aligned,....simply tightening the screw then removing the 'gauge' usually ends up with the tooth contacting the core, it typically takes a couple tweaks so be patient.

 

[Bewy]

Killer, you re-read the post. OP says he doesn't see any significant damage to the p/up. The pole piece sticks out past the coil enclosure, not by much, but that is all it has do.

There is nothing wrong with that p/up just looking at the pic & it's electrical properties will not be affected. I also provided a simple, 5 min test, to test it.

 

[Killer6]

Killer, you re-read the post. OP says he doesn't see any significant damage to the p/up. The pole piece sticks out past the coil enclosure, not by much, but that is all it has do.

There is nothing wrong with that p/up just looking at the pic & it's electrical properties will not be affected. I also provided a simple, 5 min test, to test it.

3rd pic down in post#1 does not show pole protruding, You blind as a bat mate........