Distributor cover melted

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Replacing plugs, cap, wires & rotor on the original 2F in a 1980 FJ 40

This looks like it’s melted. What does it do ? Anybody have a PN for whatever this is ? So what if it’s melted, how will this effect performance?

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It's just a dust cover to protect the points, but it should never get hot enough to melt like that.
 
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It's just a dust cover to protect the points, but it should never get hot enough to melt like that.

X2 just a cover, but no points in a 1980 unless it is from overseas.

are all the venting hoses hooked up correctly?
 
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Clearly a 78' electronic dizzy. Mine had the cover too, but it was cracked beyond use, I discarded it. If your vacuum hoses/valves aren't operating properly, you could get "farts" through the valve and into the dizzy. Your likely got some fuel vapor in it, it cooled and condensed, and then you farted, I mean your truck farted and it lit and melted. Check operation of the control valve that is supposed to prevent this. There are a few threads on here about this.
 

1911

chupacabra
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are all the venting hoses hooked up correctly?

This. The stock evacuation system keeps ozone gas from building up in the distributor. Ozone is highly flammable.
 
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So now I am a little freaked out. Doesn’t start after the ignition change out. Double checked the wires, so guess I need to see if the coil is working. But took some more pic’s showing heat on the cap & rotor. Seems more focused under the port for the red line coming from the firewall

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I was a little surprised to see what appears to be rust inside the distributor

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1911

chupacabra
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I was a little surprised to see what appears to be rust inside the distributor

Ozone, beside the possibility of detonating, is a very powerful oxidant. Again, that is why your distributor came from the factory with a vacuum evacuation system to suck ozone out of the distributor.
 
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All vents/vacuum lines were attached. However, all probably original rubber, and could be stretched out or cracked and not tightly fitting
 
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The rig has been sitting for a few years. I’ve been running 35’s for years, and just had the diff’s regeared to 4.88’s. RPM’s are higher but no tach, to say what actual RPM’s are. Went 20 miles on the freeway to break-in & change out fluids. Max speed via GPS was 64 MPH

Any chance I just spun the distributor to hot without stressing other things? (Water temps were fine)
 
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I will check that, but it seems to me, that if the heat was general by the shaft, the melting would be centered around the shaft.

I wish I understood better the components of this gen distributor
 
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Clearly a 78' electronic dizzy. Mine had the cover too, but it was cracked beyond use, I discarded it. If your vacuum hoses/valves aren't operating properly, you could get "farts" through the valve and into the dizzy. Your likely got some fuel vapor in it, it cooled and condensed, and then you farted, I mean your truck farted and it lit and melted. Check operation of the control valve that is supposed to prevent this. There are a few threads on here about this.
I search on “control valve”, but don’t see anything relevant. Is there a better or more specific search term ?
 
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Ozone, beside the possibility of detonating, is a very powerful oxidant. Again, that is why your distributor came from the factory with a vacuum evacuation system to suck ozone out of the distributor.
No. Ozone is not flammable, if its not flammable then it cannot deflagrate, if it can not deflagrate then its definitely not going be capable of achieving detonation velocities. Some simple chemistry will go a long way in unraveling these mystery's. There IS a vent system on the 78' dizzy but its purpose is to provide a DRY distributor, not one that's ozone free. If the valve fails, fuel vapors can get inside dizzy cap.
 
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The simple description of the venting for the distributor goes like this:
1) One of the hoses in the dizzy cap comes from a little (1/4" ?) stubby pipe that sticks through the passenger side firewall. If you look at the passenger side firewall you'll see a little metal box that acts as a filter and has the stubby pipe going through the firewall.

2) Another hose from the distributor cap goes to a vacuum port on the side your air cleaner. That creates a vacuum inside the distributor cap which, in turn, draws fresh dry air from inside the cab of the truck through the first hose. This system helps to reduce moisture and fumes from screwing with your points (and/or the hall-effect sensor) and the mechanical and vacuum advance parts therein.
 
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The simple description of the venting for the distributor goes like this:
1) One of the hoses in the dizzy cap comes from a little (1/4" ?) stubby pipe that sticks through the passenger side firewall. If you look at the passenger side firewall you'll see a little metal box that acts as a filter and has the stubby pipe going through the firewall.

2) Another hose from the distributor cap goes to a vacuum port on the side your air cleaner. That creates a vacuum inside the distributor cap which, in turn, draws fresh dry air from inside the cab of the truck through the first hose. This system helps to reduce moisture and fumes from screwing with your points (and/or the hall-effect sensor) and the mechanical and vacuum advance parts therein.
That airflow looks like was functioning, the nipple on the small vacuum line is the one melted, implying the air exiting the dizzy after it was heated. I Still need to figure out why the heat in the first place & fix it

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was the rig running before? IIRCC you found this when you were replacing cap and rotor.
as of right now you have no ide when this happened, was it last week or last year
 

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