No spark out distributor -

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post #1 of 3 Old 09-18-2011, 04:28 AM Thread Starter
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1991 XJ Cherokee 
Join Date: Aug 2011
Location: chandler
Posts: 231
No spark out distributor

i got a weird problem with my point type distributor on my 304 first i have this red dust on the inside of my cap and also on the points wat could cause this ? and also the motor runs rough unless i push dist cap forward and hold it it runs smooth but when i let go of the cap it get rough again i dont get spark to cylinder 1 on cap unless i physicly move my cap forward toward the front of vehicle any idea

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post #2 of 3 Old 09-18-2011, 07:52 AM
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1973 CJ5 
Join Date: Aug 2007
Location: South West Indiana
Posts: 11,180
The 'Red Dust' is the spark energy blowing through your rotor.
Since it sits right on the shaft, the spark energy blows through the rotor pretty easily and seeks 'Ground' at the distributor shaft/weights instead of going to the plugs.

The movment of your distributor and getting it to fire is a sign the distributor top busing is worn out,
Again, this is becasue of all the weight at the top of the shaft unsupported.
When you rev the engine, the weight wobbles the shaft, and the top bushing gets worn out.

My guess is if you grab the shaft, you will be able to move it side to side, and you CAN NOT tune the breaker points with that slop in the shaft/bushing.
Your 'Dwell' will be WAY OFF, and it will get worse as you increase RPM...

The 'Red Dust' is steel that has had all the carbon burned out of it.
High voltage discharges have jumped through the rotor and tried to weld the moving parts together, weights to shafts, springs to pins, advance head to shaft, ect.

Iron rusts RED, while steel rusts 'Brown',
The 'Red' is proof the carbon has been burned out of the steel, making it iron again, and once it has the carbon burned out, it rusts RED.

There are very small welds going on, and as the moving parts move during operation, the welds break and the iron slag (no carbon) breaks off and becomes 'Red Dust'.

It's MUCH more simple to replace the distributor with a rebuilt one rather than to buy all the parts,
Take the distributor apart,
And try to rebuild it yourself.
The vacuum advance alone will cost you close to $50, and the bushings, clips, advance head & pins are speciality items and they are VERY hard to find and expensive when you do.

A solid reman ready to run will cost between $50 & $100 with your distributor as an exchange.
(Pay the core charge, strip off what you need before taking the core in and getting your core charge back!
Some of those little screws and parts are hard to find and cost a fortune when you find them!)


Now, if you understand how a distributor works, you KNOW you are NEVER going to get the clearances back for a 'Contact' breaker points set...

The ONLY way to do it is a total rebuild, and that takes time (How much is your time worth) and it takes parts you can't normally buy, so when you find them in small quantities, they are EXPENSIVE...

When mine did EXACTLY the same thing, I didn't buy a new distributor,
I hauled the existing one in the shop and converted it to ELECTRONIC TRIGGER by using a Chrysler trigger from the 70's.
Again, this is a LOT of work and not worth the time/effort although it's CHEAP, around $15 to do.

It would have been much more time/money effective to switch to Jeep/Motorcraft distributor from a '78 or '79 CJ with 304 engine.
This will allow you to use about any module and coil from the FACTORY electronic ignitions.

This will also allow you to do the 'TeamRush' upgrade,
Taller rotor, to get the spark energy up off the distributor shaft,
And wider distributor cap, to keep the spark energy from cross-firing and sparking the wrong cylinder...

A VERY cost effective way to do things,
The distributor runs about $50 with core swap,
The upgraded 'Ford' cap & rotor runs about $25 to $50 depending on quality,
And you will have a distributor, cap, rotor that will serve you well for years to come.

You will need different plug wires, which runs another $65 for the really good MSD 'Blue' wires which I recommend,

And you will need a module,
That means a $20 GM HEI module, up to $160 for an MSD 6 series module.

Trust me, the MSD module is the way to go if you can afford it,
If not, it's EASY to use a $20 GM style HEI module and do some of your own wiring and it's a snap...

When you want to move up to an MSD module later, the HEI modue can be saved as a back up and the wiring is even easier than the HEI style module.


Now, a lot of people will try to talk you into a HEI Clone distributor.
I DO NOT recommend this for an AMC V-8 engine.
The HEI has the same rotor flat on the distributor shaft problem, and they make 'Red Dust' like crazy,
They have issues with caps, coils, modules, triggers, ect.

The Jeep/Motorcraft distributor has a MUCH stronger trigger from the factory, no problems with 'Red Dust', will come from the parts store with advance curve that won't harm your engine, the distributor gears are safe, ect.

It's a little more wiring, but it's worth the effort for the 'Upgrade' of the Jeep/Motorcraft distributor and factory style module or MSD module in the long run...

Do you need instructins, pictures, wiring diagrams?
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post #3 of 3 Old 09-24-2011, 10:30 PM Thread Starter
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1991 XJ Cherokee 
Join Date: Aug 2011
Location: chandler
Posts: 231
first problem i found vac advance is dead second my bushings bad third mouse ate wiring so i replace with new dist and works dandy
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