Update: 99 sable plugs/coil. Vulcan engine. U in the VIN

Jayb1961

This may help someone that has a 90's ford or Mercury 3.0 Vulcan and see that the manual shows 2 different plugs for same motor...

I got an education today on the original Vulcan plugs and coil bank. Here is the poop from what understand! …
Page 180 in the original owners manual shows AWSF-32PP(** ) as the customer replacement plug. It was the plug that replaced the 2 different plugs originally installed at the factory. Yes, the factory originally had 2 different plugs in the Vulcan engine. Most people eventually got plugs changed so thats why you don’t see engines with 2 different unique plugs anymore unless it’s the occasional low mileage “Granny only drove it to church and back.” vehicle. The parts counters would ONLY sell PP plugs as replacments. The (**) is attached to the note below.

The manual states…
“If a plug is removed for inspection it must be reinstalled in the same cylinder.
(**) Cylinders 1,2,3, have a PG suffix, cylinders 4,5,6 have a P suffix. If plug needs replacing, use only a plug with a part # suffix letter PP as shown on engine decal.”

The PP, P, and PG plugs obviously aren’t made anymore which is why actual “OEM” plugs don’t exist and never were able to be purchased. P and PG plugs were not available for customer purchase. They were ONLY supplied for the original factory install.
Here is what I found out…
Ford used a Waste Spark system. The coil pack sparks TWO spark plugs at the same time. 1+5, 2+6 and 3+4 are the match pairs that spark at the same time, their pistons are both at TDC at the same time, one on exhaust stroke the other on compression stroke. The spark happening on exhaust stroke is “wasted” so hence the name Waste Spark system. In order to fire two spark plugs from one coil they need to be wired in series, so… One spark plug sparks from center to tip, normal spark,
the other sparks from tip to center, reverse spark. This is why there are two spark plugs listed, one has platinum tip and the other a platinum center, so both are single platinum but reversed coatings. This saved Ford a lot of of money by not having to make a more expensive plug as an original install. The replacement PP plug was more expensive due to more coating and connection points but the money they saved on the single use original plugs was worth it. Motocraft SP-432, gapped at .044, is now the standard plug that most Ford dealerships install and recommend in the Vulcan engine. Motocraft is now made by Autolite and just branded differently so either equivalent is fine as a replacement.

Anyway, I changed the wires and kept the Motocraft sp-432 plugs in and everything is fine now. I definitely messed up one of the old wires when changing the plugs which was mentioned in a previous post. That is what was causing the misfire.