First off - I love my truck... but not more than my wife.

It has 2500 miles on it right now - it's an 06 LBZ/Alli crew cab 4x4.

If I'm tooling along on the freeway (Like i was today) and I was towing an empty enclosed 6x12 trailer I floored it at 65mph and it felt like a huge sag in the power, then after a few seconds it spooled up and went ok. If I'm at lower speeds say 0-30 or so it spools right up and takes off, but when on the freeway it dogs.

is this normal for this truck? I'm used to driving turbo's so I know it takes a little for spoolup, but this seems really excessive. And it's not like I'm running at say 15% power, then I floor it and it spools right up to 100%, it feels like I go from 15% down to like 5% power, then it picks up to the 100% point.

I hope that explination makes sense... anyhow - let me know your thoughts??

I do believe that your TCM is commanding a defuel, so it can down shift.

Mine does the same thing don't know why. I just ordered a Hyperpac for mine it should be in early next week, I'll let you know if this fixes the problem...:grd:

At hwy speeds I roll into the throttle. It does fine.

I agree with Metrobruce. Roll onto it and all goes fine. About 80% of my driving is fwy and I love the acceleration.

Same here, roll onto it and it does great. Less wear and tear on the truck too.

I had the same problem and my mechanic at the dealer found a leak around the turbo on the drivers side where an oring was leaking and that fixed the problem. He said he has seen that on rare occasion but it causes the same response condition. Use a flashlight and look for a approx 1 in round plug with a threaded hole in the center looking at it from the drivers side. If it is leaking oil then that could be the problem. Something to check. Good luck

"First off - I love my truck... but not more than my wife"


Must be some wife

Yup - she is a great wife... gave me a fantastic son, and let's me keep the toys! (motorcycle, new truck, camper, ect)

Anyhow, I'll try the rolling into it vs. flooring it tomorrow on the way to work, as the trailer is still hooked up from a weekend of hauling junk around.

does anyone have a power programmer and does it make a difference?

My truck does the same thing. I thought the Edge would take care of it but it doesn't. It is more noticeable with the Edge on levels 3 and 4. Not that is takes longer or doesn't anything different, it is more noticeable because when the spoolup catches up, you are thrown back into the seat. :)

Jeff

its called turbo lag and common on turbo diesels, and is alot better when you roll into the throttle rather than nail it

I don't get the same level of lagggggg on my VW turbo diesels...

they use VNT turbo's and have very quick spoolup. I drive my modded Jetta like I stole it all the time around town and struggle to get less than 35MPG...

I'm about to install a bigger intercooler and more power goodies into my VW, but the Chebby needs a little love too - it's fast stock, but I want more!

EGR valve needs to close before turbo can spool up?

It's defueling so that it can downshift without the transmission self-destructing.

Saratoga is correct. That is why most programmers will not take this out. If they did your Allison would end up all over the ground.

I take it out of sixth when towing in any type of traffic, when in fifth the mileage seems to get better and the lag is gone. Out in the open sixth seems to work well.

Cool - I have (from memory) 47 cylinders working for me... 26 of them being fed diesel fuel!

I'll try the 6th vs. 5th gear thing.

I did notice when I roll into the go pedal it does not have the super lag like if I just stomp on it. So thanks for that tip!