Diagnostic help needed - SOLVED

[Mudsport96]

Does it just do it at 80 in 4th gear? Or does it do it in 3rd as well?

 

[Tbruz]

Per the suggestion of Fless to clean the MAF and to confirm the cleanliness of the air filter; I i discovered an IMPRESSIVE size mouse/chipmunk nest in the airbox under the relatively new(less than 10 month) air filter.
I cleaned out the airbox, popped in a new air filter and spray-cleaned the MAF. I just got back from a 90+ MPH rip down the highway. I'm happy to report back that no CEL was tripped during the test ride.
Thank you to all who helped me figure out this annoying issue.

Tbruz

 

[Doubeleive]

Per the suggestion of Fless to clean the MAF and to confirm the cleanliness of the air filter; I i discovered an IMPRESSIVE size mouse/chipmunk nest in the airbox under the relatively new(less than 10 month) air filter.
I cleaned out the airbox, popped in a new air filter and spray-cleaned the MAF. I just got back from a 90+ MPH rip down the highway. I'm happy to report back that no CEL was tripped during the test ride.
Thank you to all who helped me figure out this annoying issue.

Tbruz
View attachment 405491

interesting, time for some critter traps around the parking area

 

[Mean_Green]

I had the same thing with a tractor. Put a piece of 1/4" hardware cloth over the intake. Lets air in, not critters.



But 80+ on a public highway is just not safe.

 

[Doubeleive]

I had the same thing with a tractor. Put a piece of 1/4" hardware cloth over the intake. Lets air in, not critters.



But 80+ on a public highway is just not safe.

here you might get ran off the road, big trucks are doing 70, many others are doing 85 even though the speed limit is less
I just drove thru idaho, utah, montana, nevada, speed limit there is 75-85 and no restrictions so those big trucks are hauling @ss

 

[Fless]

That's NUTS!

 

[Mudsport96]

here you might get ran off the road, big trucks are doing 70, many others are doing 85 even though the speed limit is less

Round here speed limit is 65 or 70 on the big roads, and if you aren't doing 75 80 you are impeding traffic

 

[Rocket Man]

Round here speed limit is 65 or 70 on the big roads, and if you aren't doing 75 80 you are impeding traffic

All the city freeway speeds here are 55 but 80 is the norm.

 

[RST Dana]

I haven't exceeded 80 in probably 40 years and don't see any reason to ever do so again.

You’re in the right lane I hope.

 

[nonickatall]

I haven't exceeded 80 in probably 40 years and don't see any reason to ever do so again.

Me as a German i can tell you from own experience.

Matter does not disintegrate over 80mph.

Although i was driving a porsche 180mph when i was younger, when a bird crashed into my right headlight. That led to the disintegration of matter. But this is another story.

Only, when the driver is over 80 it comes to problems.

But back to the question. When did you last time change your fuel filter, if your truck has one. Not all gmt800 have one, as far as i know. As well the air filter can be clogged.

I would start at the simple stuff.