My sig truck has a problem. About a month ago I was on a dirt road and it wasn't missing a beat. But when I got on a really rough patch the engine had a miss or a shudder. The engine didn't sound happy at all. As soon as I hit a smoother spot it was fine. I thought it may be coincidence so I turned around and went through again and the same thing happened. Hit a rough patch and doesn't run right, but get on a smooth ground and it runs great. No ticks, knocks, smoke, nothing on the smooth or rough parts. I'm leaning towards a distributor cap or wires. Has a bad connection, the bump aggravates the connection in one of the wires or the cap. Get on smooth ground and the connection is fine. I've read about this problem on here somewhere but couldn't find a thread. Need help

 

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