hummer intake valve looking at map sensor wave form

i believe what your were looking at was an event where upon every cylinder you were seeing valve overlap from other cylinders. if you count the spikes on each cylinder hump you will see increase in vaccuum cause by contribution of each cylinder because they all share intake. remember more than one intake valve is open at the same time. there is 5 distint humps going down on each cylinder event so if you are looking at number 5 cylindr you can count downward and see when each of the 5 intake valves start contributing.

I believe you are looking at intake and exhaust valve event common to the intake opening event due to overlap.

You're talking about the Hummer H3 series right?
This is part 6 to follow along for everyone else:



Definitely check out the other parts on the free channel!
www.youtube.com/playlist?list=PLAFYVCyen...vkbvE6avGuLJOQnFcx4Z