syclone01

2001 Denali Suv 6.0L AWD. Truck is stock. I do a lot of interstate driving, I tend to cruise around 80-85mph. Sometimes when I floor it from lets say 70-85mph, the truck will feel like it's missing, loosing power. I can let off the gas and it runs fine, with no miss at all. This only happens when I hit WOT. I know it's not the top speed limiter because I've been up around 105-107mph easily in the vehicle. It doesn't happen all the time. I would say maybe 10% of the time it will do it, other times it pulls up to over 100mph easily, with no hint of power loss. Check engine light is not on. Vehicle has 75k highway miles on it. I to tend to drive the truck harder than most would drive. Anybody have any ideas?
thanks, damon

11SECSS

iTrader: (175)

I would check the spark plug wires ...make sure there all pushed on...I had that happen to me with my camaro everytime I hit it it would miss but normal driving would be okay come to find out plug wire was just barley hanging on.

nightmarechevy

iTrader: (5)

Mine had a vibration at 70-75 and nowhere else and my tranny went out within a week, doubt that you have the same problem but its possible. I would also have someone check the throttle postition sensor, they can make the engine miss at a certain point but feel fine everywhere else. It makes the computer think that the throttle is closed at that point because the sensor sends the wrong signals and it causes a miss.