It stalled and now won't restart

It ran good and then we just did a little maintance. Cleaned the carb with cleaner, changed the air filter. Started the van up, let it run about 5 minutes, and drove it down the road 1 1/2 miles. Stalled. When we were trying to check the plugs to see if they were flooded, the wire broke from being dry rotted so, we changed the plugs and wires. Had the distributor switched, and the indition sensor under it checked. It still tries to tuen over but there is NO SPARK. We took of a wire and stuck a screwdriver in it and held it near the metal on the moter (a mechanic did).. but when we turn the key.. nothing, the motor turns and won't start up.