Hesitating C1500 Only at Highway Speeds and Under Load

[rccoco]

I feel ya haha. I would love to figure it out too. Any help would be appreciated! Thanks in advance

 

[Gatorboy]

I'm open to any ideas. It's probably something so simple that we have looked over it. Hopefully

 

[jeff's88silverado]

I never had that problem with a tbi truck. But i have worked on plenty with the vortec engine same symptoms and it would always be a wore distributor gear. So you could probably pull your distributor and see if the gear is wore

 

[Gatorboy]

Pull the whole distributor out?

 

[rccoco]

Hmm ill give that a try and see how the gears is. And yeah pull the whole distributer out and see how the gears are on it.

 

[Gatorboy]

let me know how yours goes

 

[Gatorboy]

So I took the truck out this morning to video the symptoms and had no problems with it. Very strange, the only thing I replaced within the last time I drove it was the EGR valve? Could this have caused the issues? Maybe the morning's cold temperature affected it.

 

[1badblue90]

okay im having the same problems as you are or as you were having .........
but for example if i run the truck cold it wont do it but once it gets the normal tempeture it does that annoying thing lol
also a more serious issue when ever i turn left and give it some good gas the engine stops like if the engine turned off then i just let off the throttle and runs normal

 

[Gatorboy]

I drove it at highway speed for ~10 miles and did not have one problem this morning. By then It was well heated up. I'm going to see how it acts on my way home when it is around 80 degrees outside.

 

[Gatorboy]

** Update

On my way home on the highway I attempted to record it. It of course happened going up hill ~45-60 mph (I live in the valley of The Smokey Mountains) so lots of hills. I recorded it but the change in Rpms when this happens is nonexistent or so small its unnoticeable. It really feels like it is coming from the rear end, not the engine. I have a light clunking noise when I put the truck in reverse but I don't think an only slightly worn U-joint would cause all this.