Technical Having an issue stalling

Really? At 1000 RPM the points in that 6-cylinder distributor are doing exactly what you described above 3000 times a minute.

Nope, not this either.

 

Well it's not a dead short. It's loaded by the primary coil winding. That's not much resistance but there's some.

Still, you're right in that if you turned the key on, and just sat there without starting the engine, and the points were closed, the condenser would burn up, and it doesn't, does it?.

But it happened to me.

I'd just put an OD trans in my Edsel, and as a temporary test run I just ran the solenoid wire up to a loose switch on the carpet & a jumper wire from the switch to the primary circuit through a hole in the fire wall. Without a grommet.

Furthermore I used a wire nut for the splice, just forward of the firewall. About 30 miles later, I stepped on the gas hard from a stop, and that wire slid back & shorted against the firewall. The car coasted to a stop with a dead condenser.

All the tuneup parts were nearly new.

I replaced the condenser and it ran fine. When I examined the old condenser the can was not swollen, but the wire literally fell off in my hand.

So supposing this wasn't the result of the short (It did short. I saw the burn mark on the firewall and the wire.) it'd be a real coincidence that my new condenser chose that exact moment to fail on its own.

However, there's a big coil in that OD solenoid. Perhaps the condenser and that coil, being linked right at the point of a stuttering short, created a big voltage spike that cooked it off?

What do you think actually happened?

 

Sounds like maybe it was running to much voltage to the points.

 

I had a stock ballast, and it had run fine for a week before I installed the OD & shorted things.

OK, somebody with more electronic experience needs to help me figure out what happened,

As I recall, coils block high frequencies and condensers pass high frequencies. ("High" being relative to their individual values.)

Here I had 2 coils of wire, both 100% grounded. (I didn't connect the governor.) & in between we have a condenser and the points making a rough 3k to 6k hz square wave. The reluctance of those coils want to "bounce" the electrons right back when the points close, at the same frequency, and higher the frequency, the harder they'll "bounce".

The ignition coil doesn't actually discharge (fire) until the bounce, and at that bounce (reversion? In accoustics it's called reversion.) at that bounce the condenser, which charged up when the points were open (edit: sorry, closed) now discharges, providing a fast spike across the coil. The ignition coil fires.

I think that perhaps when the short occurred, the spike from the condenser was in phase with and reinforced by a spike from the short (or returning from the solenoid coil?) which fried it.

I'm not sure if that makes sense, but as Ebbs pointed out my original idea about this event did not make sense. I'm still scratching my head, and this event occurred over 24 years ago.

 

I have it as lean as I can get it before the idle gets wild on me. I suspected the fuel pump being faulty because it's the easiest to rule out. Now it could be stalling because of how rich it runs. Flooding itself essentially. The fuel pump and filter hasn't been changed in who knows how long. It was on the engine when the previous owner put it in. Same goes for the points system and condenser. He hadn't been running the car much due to the trans kicking out of third. I fixed that and swapped that out. The wiring is all new. New harness new fuse box and switches. New gas lines and tank. It also has been leaking some oil from the top of the valve cover. I have two bolts it seems on top of them. The 65 didn't have those. That baffles me. The engine itself looks super clean and nothing seems out of place. New radiator as well. Like I said I am just gonna swap those things out first and assess the situation after that. So far the fuel pump is in next is the points and condenser.

 

The car fires up fine every time. No issue there. Even when it stalls it'll fire I just have to load a lot of gas into it. Cold start is no problem. Doesn't turn long either. Fires fine. Manual choke in fires ease the choke out and it idles great. Pull away great shifts fine. Just after some time it starts to bog out on me and sputter.

 

Flip that choke out and ease it in. Quick typing.

 

Might check the float for leaks. They are prone to hairline cracks.

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i once removed a manual chock off a holley 4bbl and created a vacuum leak at one of the threaded holes. it stalled during faster stops. plugged the threaded hole and no more stalling. check for vacuum leaks

 

Ulu, I'm not sure what happened in your case, but I'd highly suspect the condenser went bad first. May have simply been one that got through quality control with a loose wire lead on it..

The condensers purpose is not to discharge through the primary windings of the coil when the points open. The condenser provides a path for the high frequency voltage (spark) created in the secondary, when the points open, to go to ground. It's just a half a cycle of high frequency, so maybe I should call it "quick" instead of high frequency. In any case, if it weren't for the condenser there would be no spark, and they can fail in two ways. They can go "open" and no longer provide that path for the high frequency spark, which is what happened when the wire broke off of yours. They can also short, effectively eliminating the points and providing a constant flow of voltage through the primary windings in the coil.

 

Swapped the pump the filter points and condenser. Next is coil but this is updated to a 12 volt system. Also I'm gonna reroute the fuel line from the pump to the carb above the thermostat housing.

 

Hmmmm..I thought the condenser was to make the primary coil field collapse faster, so the field the primary coil generated in the secondary coil would be stronger.

(Reduction of point arcing being a mere side benefit.)

I think the case is stated backwards in Automotive Electrical Systems (3rd edition by Billiet & Goings) which states:

"The function of the capacitor (condenser) is to reduce the arcing at the contact points by providing a place where the current can be stored until the points are completely separated. This action also aids in the rapid collapse of the magnetic field within the ignition coil so necessary for the development of high voltage in the secondary current."

 

Did you try the "WD-40 test"?
With the engine idling as well as it will, spray some WD-40 around all the vacuum fittings and hoses, carb base, throttle shafts, intake manifold, brake booster, etc. If there's a leak, the engine will suck it in, burn it, and the RPMs will rise for a second until it burns off.

This is very useful to locate vacuum leaks.

If you have a pretty engine and don't want to spray it with oil (WD-40 will melt some paints BTW) , you can do the same thing with gas from an unlit propane torch. Spray the gas around any suspect areas and listen for the RPM to rise.

Be very careful spraying around the plugs & distributor, as any spark can start it burning.

 

You won't believe what it was. The brand new 8 dollar air breather on the carb is too small. It wasn't getting sufficient air. I pulled that off to check the butterfly and it idled perfect. Put it back on it Boggs out. Then the breather for the cam I guess is what it is needs to be cleaned. No air getting in there either. Stupid fix.

 

I'm glad you got this solved.

When you start modifying tuned systems, this is the kind of stuff you'll run into.

"It works fine except when...."

 

Good to know this one had a happy ending!

 

I love easy fixes! Glad you solved it.