Hello all,

Just got done talking with my mechanic about my truck. Most of the things he listed made sense, but he didn't have the exact cause of one. He said there were vacuum fluctuations at idle and under load. I assumed it was one of the other items, leaking fuel injectors, that could be the cause. I read online about it and an article mentioned ignition coils, or spark plugs. Any of you have experience with this and can give me any ideas of what it could be?

 

misfires cause vacuum to fluctuate

Read here about Vacuum testing, it applies to all gasoline engines, from a lawnmower to a V12, as far as vacuum goes there is no difference: https://www.gregsengine.com/using-a-vacuum-gauge.html