Paccar progressive shifting

The problem isnt the low to high jump. Low range is what sucks. How can a truck be so nurtured that it feels weaker in low range than high range. Once in the high side it starts pulling away

 

So, it started being able to keep up to a similar spec'd truck, but now doesn't. Wouldn't that suggest to you that something changed, and possibly something got damaged or needs to be changed back?

Paccar puts the rev limiter on there to keep people from over-revving the motor because they think they can get more "power" to pull over 1600 rpm. Look at the torque/hp curve I posted. It doesn't exist. There is no reason to take it up any higher.

Gone are the days of motors needing 1800-2000 rpm to get power.

 

It started pulling good when i had it deleted and tuned. But another shop wiped my tune and couldnt put it back like they told me. Thats why it sucks again. If the throttle response were just improved it wud probably solve the issue.

 

Every parameter of tuning on parts is in the ecm. There is your solution. Unless something is wrong or in need of repair.

 

Just gotta find someone to put it back like i had it without paying $3000 again. It is what it is. Thanks for all the response fellas. Good evening to yall.✌️

 

What did you drive before? A Signature 600 Cummins turned up to 750?

510/1850 in the Paccar with a 13-speed is enough to reliably pull 137,800 lbs gross and get 4.5 mpg. You should try driving a 455/1650 one with the emissions still attached/activated. You have no concept of the term "neutered".

 

455/1650 is about where im at now that they erased my tune. This is an epa 10 motor. When it was tuned i had 0 complaints and got around 6.5 mpg at 70 and now average 5.7 and weak as hell.

 

"But another shop wiped my tune and couldnt put it back like they told me."

Well, there's your problem.

It has nothing to do with the motor or how you're driving it. You already know the problem and need to get it fixed if you want it to pull right again.

 

True that. Just tired of giving money away on this tuning crap. Thats why i asked if there was a trick or anything i could unplug to disable progressive shift. Already knew the answer just thought id ask just in case. But i dont know why paccar would denut a truck that can work like a mule and get better mpg as well and make it a joke

 

I don't know about paccar ecms, but the old Detroit 60 ecms could hold 3 flash files. So I am confused. I think the last person who fiddled with your ecm don't know jack. And needs a good throat punch!