No spark

What have you checked so far? Do you have the Lean Burn ignition system or the five-pin ignition module? Did this just act up or have there been any intermittent problems leading up to this?

Which ignition system do you have?

There are some common things to look for. Both ignition systems use a pick-up coil in the distributor, but the distributors are different. The Lean Burn distributor does not have a vacuum advance unit on the passenger side, and there's no mechanical advance flyweights in it. That pick-up coil can develop a corroded connection on one of its wire ends. That commonly causes the engine to stall when that coil gets warm. Often the engine runs fine as long as there's natural air flow through the engine compartment, but once you stop with a hot engine, as in when stopping for gas, engine heat migrates up to the distributor, causing that failure. The engine will typically start again after cooling down for about an hour.

If you have the 5-pin ingintion module, (with only four wires in its connector), that module gets its ground through the case and mounting bolts. Rust and loose bolts will cause intermittent problems. If that looks questionable, bolt on a piece of wire and run that to some other place that is rust and paint-free, and bolt it there.

The Lean Burn Computers on occassion would develop broken solder connections where the connector is soldered to the circuit board. I never had one apart for that, but I have heard of it. This was a real common problem years ago on tvs. A little careful soldering eliminated the need to replace the modules.

If you have the white ballast resistor on the firewall, check those connections. They aren't well protected from moisture, so the terminals could become rusty. That usually causes a problem after they have been disturbed or unplugged.

The ignition coil could be intermittent too, but that isn't real common.

I did run into a few shorted 5-pin ignition modules. The easiest clue to look for is to pull off the coil wire at the center of the distributor cap, and check for spark, but while there will be no spark during cranking, you will see one nice strong spark when your helper turns the ignition switch off. That spark is supposed to occur when the module turns current flow off through the coil, but when the module is shorted, it stays turned on, then the ignition switch performs that switching action instead. Shorted ignition modules are usually a permanent failure. I've never seen one be intermittent, except for the rusty or loose mounting bolts.

Some distributors had two pick-up coils and two pairs of wires, each pair going to a two-terminal plug. Those were usually orange and black wires. If you find that, there will also be a relay that switches between those two coils. That relay is another good suspect.

One of the pick-up coils is used during engine cranking. It is set for retarded ignition timing for easier starting. Once the engine is running and the ignition switch is released, the relay switches in the other pick-up coil to run on.

The clue here if one pick-up coil is bad is the engine will only run during cranking, or it will only start running the instant you release the ignition switch This assumes the relay is switching normally. If it is not, or has arced or pitted contacts, the engine may not run at any time.

To further complicate this, there was also a real common problem with the dual ballast resistor. Those almost always failed after prolonged idling, as in when sitting at a red light. The clue here was the engine would only run while holding the ignition switch in the "crank" position. A separate tap on the ignition switch bypassed that resistor for a stronger spark to make up for the battery being loaded down by the starter. Once the ignition switch was released, current had to go through the ballast resistor to get to the ignition coil, so when the resistor was burned open, there was no spark except during cranking. If you knew about this common problem, you could work around it on most models by holding the ignition switch in the "crank" position with one hand, and shifting into "drive" with your other hand. The ignition switch in the "crank" position kept the resistor bypassed, and the neutral safety switch turned off the starter system. This was such a common problem for a few years that a lot of owners carried spare resistors in the glove box.

By at least 1980, (as on my Volare), one of the five wires was dropped at the 5-pin ignition module, and instead of that dual ballast resistor, they went back to the common single resistor as had been used for a real long time. They never had that common resistor failure once they went back to that single resistor. I can't remember if they used a ballast resistor with the Lean Burn system. I had four cars with that system, but never had to diagnose anything on them.

About 95 percent of these cars only had one pick-up coil in the distributor, so you'll find a single black, two-terminal connector. If you suspect it is failing when it gets warm, once the stalling occurs, unplug that connector, then use an ohm meter to measure the resistance between those two wires on the distributor side. If you need it, the second half of this article shows how to use an ohm meter. If you have a standard meter that you have to select the ranges on, I can help with that, if necessary:

https://www.2carpros.com/articles/how-to-use-a-voltmeter

Typical resistance for this pick-up coil is around 700 - 750 ohms, although some service manuals list it as high as 1150 ohms. The actual value is not that important, because the resitance won't change on its own. What we expect to see with a failed pick-up coil is an open circuit, meaning "infinite". That's caused by one end of the coil of wire breaking off at the terminal it's soldered to. You're only going to find 0 ohms, infinite, or some resistance value in between. Zero ohms is almost impossible because the two ends of the wire are too far apart to physically short together. If you don't have 0 ohms, and you don't have an open circuit, you have to have the resistance value that's normal for that pick-up coil. If you measure three coils, you'll get three different resistances, and they'll all work just fine. That proves the actual value is not important as far as diagnostics are concerned.

When you have the 5-pin ingition module, you'll also have the vavuum advance unit on the distributor. When that operates, it moves the plate the pick-up coil sits on, and that causes flexing of those two wires. That's another way the pick-up coil can fail. With your Lean Burn system, vacuum advance is handled by a transducter on the computer module, so those flexing wires are one thing you don't have to worry about.

Before you disturb a lot of stuff and potentially add more variables, be sure to check first if you're really losing spark. If you're not, this could be a fuel supply problem. The best suspect for that is a plugged strainer inside the gas tank.

Sorry to hear you didn't curl your hair, but at least we know we're in the right system. Do the resistance check, then tell me what you find.

I think there may be two versions of this distributor. The first time I replaced a pick-up coil, all I had to do was remove a small screw and lift the assembly out. It was no different than replacing a set of breaker points. On a different one, I had to remove the entire distributor, remove the roll pin and gear on the bottom of the shaft, slide the shaft up and out, then remove two screws across from each other on the outside of the housing. That allowed the plate to be lifted up with the pick-up coil on it. I can't remember for sure, but I think that coil was riveted to the plate. As such, I also can't remember how that air gap was adjusted. That air gap is critical. In one service manual it was listed at 0.018" and in another it was 0.012". You must use a brass, or non-magnetic feeler gauge. A steel gauge will stick to the magnet that is at the center of the coil, and give a false feel.

I had one once on one of my cars where I wanted to replace the rotor and cap, but I couldn't get the rotor off. Ended up cracking it with a screwdriver and hammer, but while I got it off in two pieces, I caused a lot more trouble. I bent the shaft, but was able to bent it back straight, but then I had a crank / no-start condition. Turns out, when the rotor split apart, it pushed on the pick-up coil and increased the air gap to around 0.020". Readjusted it to 0.012" and the engine fired right up.