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Truck is a 1995 NAS V8 with just over 100k on the clock. Has been running great until the other day when I experienced a loss of power and backfire/pop out of the intake when modestly accelerating away from a stop. Off the throttle, the engine immediately returned to a smooth idle. I was able to limp home by being very light on the throttle from a stop which would get the truck rolling, and while it run somewhat smoothly above maybe 2000 rpm, it seemed like it might have been down on power.
Got under the hood today and at a quick glace the HT leads, plugs, and cap look refreshed (likely replaced just before I purchased in early 2020) with no obvious broken wires, unplugged terminals, or broken vacuum lines. There was however some questionable shadetree wiring (see attached pictures) in the vicinity of the coil, including a 3 pin molex type connector that was not connected to anything at all. The coil also appears to be original. I removed the coil, reseated everything and was then faced with a crank, no start situation. I double checked everything on the bottom of the coil was in place with my fingers, and then it cranked right up on the first try. Idles smooth, but still wants to die completely off idle albeit with less aggressive popping (perhaps due to a cold motor this time?)
I'm pretty lost when it comes to ignition systems in general, and even more so with distributor systems. Googling the popping/no power symptoms returns everything from bad plugs to a burnt exhaust valve. Being that after manipulating the coil wiring I had no spark, I would tend to want to focus my investigation there, but it's also throwing me for a loop that the truck idles perfectly fine. Are there any clear connections between my set of issues and a particular failure mode of the coil?
Got under the hood today and at a quick glace the HT leads, plugs, and cap look refreshed (likely replaced just before I purchased in early 2020) with no obvious broken wires, unplugged terminals, or broken vacuum lines. There was however some questionable shadetree wiring (see attached pictures) in the vicinity of the coil, including a 3 pin molex type connector that was not connected to anything at all. The coil also appears to be original. I removed the coil, reseated everything and was then faced with a crank, no start situation. I double checked everything on the bottom of the coil was in place with my fingers, and then it cranked right up on the first try. Idles smooth, but still wants to die completely off idle albeit with less aggressive popping (perhaps due to a cold motor this time?)
I'm pretty lost when it comes to ignition systems in general, and even more so with distributor systems. Googling the popping/no power symptoms returns everything from bad plugs to a burnt exhaust valve. Being that after manipulating the coil wiring I had no spark, I would tend to want to focus my investigation there, but it's also throwing me for a loop that the truck idles perfectly fine. Are there any clear connections between my set of issues and a particular failure mode of the coil?
