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I noticed that your car started after you replaced the plug wires, but I also wanted to inform you of another common issue with 700 series Volvos that will cause a no-start condition in damp weather.
Sandwitched between the distributor cap and the distributor itself is supposed to be a large black "splash guard" disc. This disc mounts first, under the rotor, and then the rotor is installed, followed by the cap. The disc contains a rubber seal on the outside edge and prevents water from entering the distributor cap. If this disc is missing, the cap will not provide the appropriate seal against the distributor, and damp air and water can EASILY enter the spark-transfer area between the rotor and the cap.
As a distributor cap is used, spark transfer surfaces begin to accumulate carbon deposits (as the copper slowly burns away from normal wear/operation). The carbon deposits do create a bit of extra resistance, which is negligable under most conditions. However, if the carbon deposits get wet or damp, they can completely stop the spark transfer from the rotor to the cap. This is why it's very important that a distributor maintain a decent level of dryness, even under wet or damp conditions.
Most non-Volvo trained mechanics are not even aware that the cap is present on the 700 series rear-mount distributors. Needless to say, when they remove the cap and rotor, the splash guard disc often falls off the distributor and drops to the floor of the garage. After installing a new cap & rotor, and the customer has driven away, they find this random black disc on the garage floor. Seeing that the car drove away fine without the disc, they toss it in the garbage and think nothing of it. They don't realize that they just created a potential problem that might keep the car from starting in damp wether, -or might cause it to stall if driven through a large puddle where the engine bay is splashed with water.
FYI, when a no-start condition is caused by this problem, the Fuel Injection system will continue to deliver fuel to the injectors (thus creating the smell of excess fuel). When installing plug wires, I encourage using some dielectric grease on the spark plug wire terminals (at both ends of each wire) to help keep moisture from getting into areas that can inhibit spark transfer, as this can cause a dead cylinder. Regarding ignition problems in damp weather, if the car starts hard and seems like it's missing on one or two cylinders, this is probably due to an issue with the plug wires. If it doesn't fire at all, this is often caused by a lack of a splash guard in the distributor, or a bad primary ignition wire between the ignition coil and the rotor.
God bless,
Fitz Fitzgerald.
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'87 Blue 240 Wagon, 268k miles.
'88 Black 780, PRV-6, 149k miles.
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