Community Forums

rvadventure · 06-14-2018, 05:06 PM

Recently I took the coach in to a truck shop and they changed my serpentine belt, and did the software updates. When I picked it up it didn’t seem to have as much get up and go, but I thought it was my imagination. I headed up the mountain today and I really had a lot less power than usual. If I put it on cruise control it goes like it always did. I’m not sure what happened? Any ideas? The engine is a cummins 425 HP. ISL. Regards

FatChance · 06-14-2018, 05:15 PM

What response did the shop that did the work tell you when you called?

ThePowells · 06-14-2018, 05:22 PM

It is possible that a previous owner or shop changed the engine profile to add HP or torque and the update restored the factory settings.

A Traveler · 06-14-2018, 06:56 PM

Quote:

Originally Posted by rvadventure

...If I put it on cruise control it goes like it always did....

This confirms that there is nothing wrong with the engine or it’s programming. It also confirms that there IS something wrong with the throttle position sensor. You can push the pedal all the way to the floor, but the engine doesn’t know it’s wide open.

ThePowells · 06-14-2018, 07:57 PM

I don't know about now, but I know that the early DD60 engines would produce what ever was programmed, but would produce max rated HP when the cruise was on and the set / accel switch toggle was held in the accel position.

rvadventure · 06-14-2018, 08:35 PM

Quote:

Originally Posted by FatChance

What response did the shop that did the work tell you when you called?

I haven’t asked them yet, mainly due to I don’t have a lot of confidence in them. My mistake I didn’t take it where I normally due because they had 40 jobs ahead of me, but they do great work. Thank you

rvadventure · 06-14-2018, 08:38 PM

Quote:

Originally Posted by ThePowells

It is possible that a previous owner or shop changed the engine profile to add HP or torque and the update restored the factory settings.

I’ve had the updates done since then, not sure what caused it, but I’m taking it to my regular shop that has done work on all of my coaches. Thanks for the response. Regards

**TonyDi** · 06-14-2018, 08:40 PM

I also agree that you have a problem with the throttle position sensor. If cruise control acts normal there's no engine problem such as clogged fuel filters etc. It's not convenient but use the cruise control until you can get it to your mechanic.

rvadventure · 06-14-2018, 08:40 PM

Quote:

Originally Posted by A Traveler

This confirms that there is nothing wrong with the engine or it’s programming. It also confirms that there IS something wrong with the throttle position sensor. You can push the pedal all the way to the floor, but the engine doesn’t know it’s wide open.

I think you are right on with this assessment, I called my regular shop and they said pretty much the same thing. Thanks for the response. Regards

rvadventure · 06-14-2018, 08:42 PM

Not sure either, thanks for the response. Regards

rvadventure · 06-14-2018, 08:44 PM

Quote:

Originally Posted by TonyDi

I also agree that you have a problem with the throttle position sensor. If cruise control acts normal there's no engine problem such as clogged fuel filters etc. It's not convenient but use the cruise control until you can get it to your mechanic.

Thanks Tony, Hopefully they can just replace the sensor, once you do the update I don’t think you can reverse them, if that is what caused it. Regards

OLYLEN · 06-15-2018, 08:51 AM

What is your boost pressure while on full load both cruise ad foot throttle? Good tell on power out put.

LEN

rvadventure · 06-18-2018, 05:58 PM

Quote:

Originally Posted by rvadventure

Recently I took the coach in to a truck shop and they changed my serpentine belt, and did the software updates. When I picked it up it didn’t seem to have as much get up and go, but I thought it was my imagination. I headed up the mountain today and I really had a lot less power than usual. If I put it on cruise control it goes like it always did. I’m not sure what happened? Any ideas? The engine is a cummins 425 HP. ISL. Regards

Well I had an appointment to get this issue looked at, but over the weekend I started looking at threads, and as usual people on this forum came up with the answer. I found a thread from 2011 that gave the instructions on how to calibrate you acellerator to the engine and transmission. I took a picture of the instructions, but didn’t get the ID of the person who posted it. So whoever did this post I thank you, and will also post these easy to do instructions. My coach ran like a bat out of hell after I did the re- calibration. Regards