 |
|
03-04-2021, 02:54 PM
|
#1
|
|
Member
Join Date: Feb 2021
Posts: 47
|
No throttle until coach is moving??
Starts and idles great. Put it in gear.. No throttle response till it is moving over 5 miles an hour.. Takes off after 5mph.. What could possible cause this??
98 Fleetwood
Frieghtliner XL
Cummins ISB275
Allison 6 speed auto
Any help would be much appreciated
Thx
|
|
|
 |
Join the #1 RV Forum Today - It's Totally Free!
iRV2.com RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!
You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!
|
|
03-05-2021, 08:33 AM
|
#2
|
|
Community Moderator
Winnebago Owners Club Freightliner Owners Club
Join Date: Dec 2003
Location: Weyauwega, WI US
Posts: 7,346
|
My suggestion is call the 24/7 help line at 800-385-4357. They should be able to help you. Have your VIN number handy.
Don
__________________
Don & Bev Morgan Weyauwega WI, 05 Itasca Horizon 40KD, 400 HP Cummins, Adopted by a great couple, Toad 07 Saturn Vue AWD, Air Force One, TST 510 TPMS, Mayor of Weyauwega 2007 - 2013, Waupaca Co Board Supervisor 2010 - 2014
|
|
|
|
|
03-05-2021, 10:04 AM
|
#3
|
|
Senior Member
Fleetwood Owners Club Freightliner Owners Club
Join Date: Feb 2012
Location: North Little Rock, Arkansas
Posts: 756
|
I replaced a MAP sensor on the intake manifold (near transmission side of engine) for sluggish response from startup. IIRC I purchased on the road from an O'Reilly and had to also get a large socket for it.
How are your boost levels? If there is a boost leak somewhere, it can cause sluggish turbo response also.
Best of luck.
__________________
2008 Fleetwood Bounder 38S, 6.7 ISB-Flat tow-2015 Cherokee Trailhawk
Richard & Margaret with Shih-Tzu 'Charley' 
|
|
|
|
|
03-05-2021, 10:41 AM
|
#4
|
|
Senior Member
Join Date: Dec 2009
Location: Out there, somewhere
Posts: 8,791
|
Hmmmmm,
This is an odd one. I'm wondering, how does one get about 15 tons of coach moving, if it's slightly uphill on a take off, if you have no throttle 'till after 5+ mph? Not all driving or take-offs are level or downhill. Other than those questions I'm sorry I don't have a suggestion to try. Kind-a interested in the actual answer though, just in case it happens to me on our '04 Itasca Horizon 36GD with the CAT C-7 330HP.
Scott
__________________
2004 ITASCA HORIZON 36GD, 2011 GMC Sierra 1500 4x4 Toad '18 Honda Africa Twin Adventure Sports DCT 
Retired-29.5 yrs, SDFD, Ham - KI6OND
Me, Karla and the Sophie character, (mini Schnauzer)
|
|
|
|
|
03-05-2021, 01:00 PM
|
#5
|
|
Member
Join Date: Feb 2021
Posts: 47
|
Thx
Quote:
Originally Posted by mevman
I replaced a MAP sensor on the intake manifold (near transmission side of engine) for sluggish response from startup. IIRC I purchased on the road from an O'Reilly and had to also get a large socket for it.
How are your boost levels? If there is a boost leak somewhere, it can cause sluggish turbo response also.
Best of luck.
|
|
|
|
|
|
03-05-2021, 01:08 PM
|
#6
|
|
Member
Join Date: Feb 2021
Posts: 47
|
It barely moves idling, even on a slight up hill. Throttle gives 50 to 150 rpms. Changes from time to time... It feels like I just barely crack the throttle... Till it reaches 1500 rpms. Then it takes off..
Like normal... Under 1500 it just creeps..
Takes over a minute or two to get to the slight hill. Then over 1500 it runs great... Shifts great.. Pulls hard...
Quote:
Originally Posted by FIRE UP
Hmmmmm,
This is an odd one. I'm wondering, how does one get about 15 tons of coach moving, if it's slightly uphill on a take off, if you have no throttle 'till after 5+ mph? Not all driving or take-offs are level or downhill. Other than those questions I'm sorry I don't have a suggestion to try. Kind-a interested in the actual answer though, just in case it happens to me on our '04 Itasca Horizon 36GD with the CAT C-7 330HP.
Scott
|
|
|
|
|
|
03-05-2021, 01:58 PM
|
#7
|
|
Senior Member
Join Date: Feb 2015
Location: Huntingtown, MD
Posts: 691
|
I have experienced the same thing 3 different times. When this has happened I replaced both fuel filters and always ran fine afterword. The fuel filters were never old prior to sluggish acceleration problem.
__________________
Earl & Sharon, 2008 Fleetwood Expedition, ISB 6.7
1995 Jeep YJ/2013 Chevy Sonic
|
|
|
|
|
03-05-2021, 02:39 PM
|
#8
|
|
Junior Member
Join Date: Feb 2020
Posts: 9
|
Quote:
Originally Posted by 98fleetwood
Starts and idles great. Put it in gear.. No throttle response till it is moving over 5 miles an hour.. Takes off after 5mph.. What could possible cause this??
98 Fleetwood
Frieghtliner XL
Cummins ISB275
Allison 6 speed auto
Any help would be much appreciated
Thx
|
I also have the ISB RV275 motor in my Ford F800. There's a parameter in the programming that limits the engine RPM until it sees enough mph. When you weigh 30,000lb and are trying to get moving on grade you're effectively stuck. Had a shop change the parameter from 1500 RPM to 3000, problem solved.
__________________
2017 Jayco Designer 37rs 2007 Volvo VNL 670
|
|
|
|
|
03-05-2021, 03:59 PM
|
#9
|
|
Member
Join Date: Feb 2021
Posts: 47
|
Interesting
Quote:
Originally Posted by rollinbrian
I also have the ISB RV275 motor in my Ford F800. There's a parameter in the programming that limits the engine RPM until it sees enough mph. When you weigh 30,000lb and are trying to get moving on grade you're effectively stuck. Had a shop change the parameter from 1500 RPM to 3000, problem solved.
|
|
|
|
|
|
03-06-2021, 07:39 AM
|
#10
|
|
Member
Join Date: Apr 2016
Location: Edmonton Alberta
Posts: 63
|
Please keep us up dated?
|
|
|
|
|
03-06-2021, 09:58 AM
|
#11
|
|
Senior Member
Join Date: Dec 2009
Location: Out there, somewhere
Posts: 8,791
|
Quote:
Originally Posted by rollinbrian
I also have the ISB RV275 motor in my Ford F800. There's a parameter in the programming that limits the engine RPM until it sees enough mph. When you weigh 30,000lb and are trying to get moving on grade you're effectively stuck. Had a shop change the parameter from 1500 RPM to 3000, problem solved.
|
It's called *Torque rise*. The diesels put out so much torque in such low rpms that, if not limited, some of them can tear up a drive train somewhat easily. We had the same things in all our FD trucks. The OP's rig may have slipped out of adjustment or, has developed other issues related to the throttle.
Scott
__________________
2004 ITASCA HORIZON 36GD, 2011 GMC Sierra 1500 4x4 Toad '18 Honda Africa Twin Adventure Sports DCT
Retired-29.5 yrs, SDFD, Ham - KI6OND
Me, Karla and the Sophie character, (mini Schnauzer)
|
|
|
|
|
03-06-2021, 10:35 AM
|
#12
|
|
Senior Member
Join Date: Jul 2014
Posts: 26,835
|
If you ever watched truck or tractor pulls, you would see what happen when you add full fuel to a low RPM diesel engine. Black smoke !
Before pollution regulations or controls, diesels had stacks to blow the smoke up away from the cars.
Our old, 1985, Mack trucks had " Puff limiters ". They restricted the fuel flow until the manifold pressure ( boost ) was high enough to burn cleaner. When they failed, the engine smoked black on take off or was lame, lacking power.
All of that fuel control is done electronically now.
Your slow takeoff may be a sensor out of range.
|
|
|
|
|
03-07-2021, 06:31 AM
|
#13
|
|
Member
Join Date: Feb 2021
Posts: 47
|
I am having the VP44 rebuilt...
Just hope I am not pissing in the wind..
More to come.....
Quote:
Originally Posted by basketball
Please keep us up dated?
|
|
|
|
|
|
03-10-2021, 06:17 PM
|
#14
|
|
Member
Join Date: Feb 2021
Posts: 47
|
It was the VP44.
Thanx for anyone's input!!
|
|
|
|
|
|
|
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
|
|
|
| Thread Tools |
Search this Thread |
|
|
|
| Display Modes |
 Linear Mode
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
|
» Recent Discussions |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
