Listen to this noise...

-
The distributor speed is always half of crank speed. This is because of the timing sprockets and chain, crank sprocket is always half the size of the cam sprocket. the cam gear is always the same size of the distributor drive gear. Hence the distributor shaft speed is always half of crankshaft speed.
Me I would pull off the converter shield and check...at least to have a look see...….

That's true, BUT the rotor spinning diameter is MUCH smaller than the flex plate and converter. The noise is distributor rotor speed.
 
It's the rapid fire of the coil...like a sci fi movie laser gun.

Its not check plate being hit by convertor bolts, that sounds different and more tin can sounding.
 
If the ring gear teeth on the converter rubbing on the shield would it not make the same noise? Would it not come and go as the OP stated in his first post.
There is a noise that is made when I am in drive or reverse with my foot on the brake.
I am pretty sure if that noise is coming from the distributor you should be able to grab the cap and would feel this..would you not?
 
If the ring gear teeth on the converter rubbing on the shield would it not make the same noise? Would it not come and go as the OP stated in his first post.

I am pretty sure if that noise is coming from the distributor you should be able to grab the cap and would feel this..would you not?

You would think......but the OP also said "I don't know what to do next", so you have to weigh THAT into consideration.
 
You would think......but the OP also said "I don't know what to do next", so you have to weigh THAT into consideration.
OP should pull the coil wire...have it hang with the end about a 1/4 away from the head or block...and turn the key to run position...and then watch the wire arch like a mig
 
OP should pull the coil wire...have it hang with the end about a 1/4 away from the head or block...and turn the key to run position...and then watch the wire arch like a mig

You may well be right.....my hearing is SHOT but it just does not sound like something firing to me.
 
You may well be right.....my hearing is SHOT but it just does not sound like something firing to me.
When the Box goes bad in this way it sends everything at once, there is no dwell limit its...full blast..and the further the ark, the louder.....so when the revs pick up..it begins hitting a target/ground more, ark shortens to normalish n quiets more as the rpm increases and rotor keeps up

It's a noise you never forget.
 
When the Box goes bad in this way it sends everything at once, there is no dwell limit its...full blast..and so when the revs pick up..it now hitting a target more as the rpm increases and so the noise gets less.

It's a noise you never forget.

You are probably right on.
 
You are probably right on.
Its thousands of miles away and through a video on a cell phone...so if I weren't, idgaf. Lol but really that sound is unforgettable.
I edited my post before this after you quoted me. I don't type as fast as I think and so my post get jumbled when I'm trying to get it out there quickly
 
It's the coil firing.. caused by the ignition box , its constantly firing the coil.
I've had this happen with a orange box going bad right out of the box..

Seems pretty loud to be that to me.
Also sounds mechanical and not electrical.

In any case it seems we covered about every possibility.:D
 
The contacts inside the cap are worn because the rotor is hitting them. The rotor has about an 1/8 of an inch of vertical play and about 3-4 degrees axial. From all your comments I believe this to be the problem. Now what would be causing the rotor to have so much play and what would be the remedy? You guys are awesome!
 
Keep checking that cap and rotor. Could it possibly be an advance weight at idle that swings free when you rev it? It may have lost a shaft bushing allowing it to move up and down under load. Pull it and see if there is more than about .010 axial shaft play. Should be almost nill.
View attachment 1715519163

rotor should swing in under contacts as well as past (step shaped) them so too much axial play would tear up the contacts on top of rotor. See the step? Makr sure rotor is seated. Need them pics!~
View attachment 1715519182
Yes when I removed the cap the rotor can move up and down by hand. The contacts are all getting worn down on the cap at the bottom of the step and starts to grind into the plastic. Fairly sure you found the answer with that shaft bushing.
 
The contacts inside the cap are worn because the rotor is hitting them. The rotor has about an 1/8 of an inch of vertical play and about 3-4 degrees axial. From all your comments I believe this to be the problem. Now what would be causing the rotor to have so much play and what would be the remedy? You guys are awesome!

It's normal for the rotor to have rotational travel at rest. Probably on the order of as much as 20* worth, because that is the mechanical advance working. As far as vertical play, that should be a minimum.

I tell you what I did to mine. I bought it in January of 2019. It had sat up since 1980. Once I did a compression test and found everything good, I did a major tuneup including a reman distributor. It just made sense.
 
The contacts inside the cap are worn because the rotor is hitting them. The rotor has about an 1/8 of an inch of vertical play and about 3-4 degrees axial. From all your comments I believe this to be the problem. Now what would be causing the rotor to have so much play and what would be the remedy? You guys are awesome!
So how does one miss part interference?
If that is the case.

The rotor will move from the mechanical advance gives some stationary
 
Nylon distributor gear strikes again??
Hmm mark distributor and block then pull cap and mark rotor to body and remove...
Inspect gear, post pics.

I lost a couple teeth at a time, but never had that sound... it would just start idling like **** and even die...then you would pull the cap and the rotor FREELY moved a lot .

The mechanical advance allows 'some' movement..but you feel spring resistance
 
It's the coil firing.. caused by the ignition box , its constantly firing the coil.
I've had this happen with a orange box going bad right out of the box..

Seems to run awfully smooth for that to be happening.
 
CF6060C1-835B-4997-A96E-03996ACBDAC4.jpeg
47880CB6-2033-4324-95BA-B87642C2EDD7.jpeg
 
@Scanch, would you do us a favor, and put the cap back on, start the car make sure the noise is there and rest your hand on the distributor (not the wires)… And then lay next to the car reach your arm out and just touch the converter shield and tell us where you feel the noise......
 
Last edited:
-
Back
Top