Distributor cover melted
- Thread starter aktundra
- Start date
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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?
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.
This. The stock evacuation system keeps ozone gas from building up in the distributor. Ozone is highly flammable.
Ozone is inflammable.
- Thread starter
- #7
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
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.
The rest of the diagram may or may not be the same, but the venting of the distributor cap is the same. Was it hooked up like this?
- Thread starter
- #12
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)
Any chance I just spun the distributor to hot without stressing other things? (Water temps were fine)
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You could pull the distributor so you could see how free the shaft bearing turns / feels.
- Thread starter
- #15
I search on “control valve”, but don’t see anything relevant. Is there a better or more specific search term ?
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Look at VSV for distributor ventilation in the schematic above.
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.
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.
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.
- Thread starter
- #19
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
