LB7: Limited to 2000 rpms HELP - Diesel Place : Chevrolet and GMC Diesel Truck Forums
 
Home Forum Market Place Garage Lounge (0) Tuning Library DTC Tool Register Vendors
Go Back   Diesel Place : Chevrolet and GMC Diesel Truck Forums > GM Diesel Engines > Duramax First Generation: 2001-2004 (LB7)
Register FAQ Forum Rules My Replies My Threads Mark Forums Read Auto EscrowAuto LoansInsurance

DieselPlace.com is the premier Duramax Diesel Forum on the internet. Registered Users do not see the above ads.
Reply
 
LinkBack Thread Tools
Old 11-30-2012, 12:43 PM   #1 (permalink)
willydmax
Diesel Fanatic
 
Join Date: Dec 2005
Location: MO
Posts: 54
iTrader Score: 0 reviews

Limited to 2000 rpms HELP

Just got done replacing all 8 injectors in Dad's 02. After a bit of cranking she fired up and idled perfect then when I went to rev it up it won't rev past 2000 rpms. It has 211000 miles on it, KD Mega filter, KD dual lift pumps, new filters. I put Kennedy's restriction gauge on it and it shows 7.5 psi. There's no check engine light. Dad has a scan tool (Innova Can OBD2&1) and it says there are no stored codes. Maybe the scan tool isn't any good? What do you think? This is the second time I've replaced the injectors myself. Last time was at 160,000 miles back in 2010. I am at a standstill so far. Thanks!
__________________
05 GMC 2500HD Crewcab shortbed
Duramax Allison 4x4
265 Michelns
UNI air filter,fumoto drain valve
FilterMag on oil,fuel,& allison filters
Post oem Mega fuel filter
Air Lift air bags with sure set controller
Peragon aluminum bed cover
B&W turnover ball
Rhino liner
Sold... due to spending mission time in Romania since 2007
Offline  
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Old 11-30-2012, 01:03 PM   #2 (permalink)
THEFERMANATOR
Diesel Sr. Technical Member
 
Join Date: Aug 2005
Posts: 5,355
iTrader Score: 0 reviews

Check the MAF sensor as any prolem with it and teh ECM will go into limp and restrict you to 2K RPM's.
Offline   Reply With Quote Quick reply to this message
Old 11-30-2012, 01:06 PM   #3 (permalink)
willydmax
Diesel Fanatic
 
Join Date: Dec 2005
Location: MO
Posts: 54
iTrader Score: 0 reviews

I sprayed it with some carb cleaner and blew it dry with air along with the connectors. Is that all I can do with it or is there a way to diagnose it?
__________________
05 GMC 2500HD Crewcab shortbed
Duramax Allison 4x4
265 Michelns
UNI air filter,fumoto drain valve
FilterMag on oil,fuel,& allison filters
Post oem Mega fuel filter
Air Lift air bags with sure set controller
Peragon aluminum bed cover
B&W turnover ball
Rhino liner
Sold... due to spending mission time in Romania since 2007
Offline   Reply With Quote Quick reply to this message
Old 11-30-2012, 04:09 PM   #4 (permalink)
willydmax
Diesel Fanatic
 
Join Date: Dec 2005
Location: MO
Posts: 54
iTrader Score: 0 reviews

Still trying to figure this out. I am in the process of taking connectors apart and spraying them with contact cleaner in hopes that will fix it. It just seems strange to me that it acts like its in limp mode without any codes. Any thoughts?
__________________
05 GMC 2500HD Crewcab shortbed
Duramax Allison 4x4
265 Michelns
UNI air filter,fumoto drain valve
FilterMag on oil,fuel,& allison filters
Post oem Mega fuel filter
Air Lift air bags with sure set controller
Peragon aluminum bed cover
B&W turnover ball
Rhino liner
Sold... due to spending mission time in Romania since 2007
Offline   Reply With Quote Quick reply to this message
Old 11-30-2012, 05:56 PM   #5 (permalink)
willydmax
Diesel Fanatic
 
Join Date: Dec 2005
Location: MO
Posts: 54
iTrader Score: 0 reviews

Update

Well I put her all back together and took her for a spin to see what would happen and lo and behold she runs perfect! I don't know if Kennedys tuned ECM has something in it to limit it to 2000 rpms sitting in park or if I still have an issue. Whatever the case I am very pleased that its running great! Thanks for the help.
__________________
05 GMC 2500HD Crewcab shortbed
Duramax Allison 4x4
265 Michelns
UNI air filter,fumoto drain valve
FilterMag on oil,fuel,& allison filters
Post oem Mega fuel filter
Air Lift air bags with sure set controller
Peragon aluminum bed cover
B&W turnover ball
Rhino liner
Sold... due to spending mission time in Romania since 2007
Offline   Reply With Quote Quick reply to this message
Old 12-01-2012, 01:04 PM   #6 (permalink)
THEFERMANATOR
Diesel Sr. Technical Member
 
Join Date: Aug 2005
Posts: 5,355
iTrader Score: 0 reviews

Quote:
Originally Posted by willydmax View Post
I sprayed it with some carb cleaner and blew it dry with air along with the connectors. Is that all I can do with it or is there a way to diagnose it?
I would say you need to be prepared to replace your MAF sensor REAL soon as carb cleaner DESTROYS them. you NEVER EVER use carb cleaner, even many MAF cleaners can harm the circuit board on them. Electrical contact cleaner is the safest cleaner to use on them. And blow drying it with compressed air can break the MAF element off as well. And yes many operating systems are limited in RPM's in neutral.
Offline   Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Diesel Place : Chevrolet and GMC Diesel Truck Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

PLEASE READ! You must check your email inbox for the confirmation link to complete registration. Please check your spam box if you do not see the email in your inbox.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Vibration @ 2000 rpms? EricJ 6.5L Diesel Engine 4 10-06-2011 01:25 PM
wont rev over 2000 rpms Norvell57 Duramax Third Generation: 2006-2007.5 (LBZ & LLY) 5 02-26-2009 09:11 PM
Got P0700 code and under hilly condition the RPMs get limited to 2k. george7g Duramax Second Generation: 2004.5-2005 (LLY) 21 07-14-2007 11:03 AM
other day truck wouldn't go over 2000 RPMS ChevyManSC Duramax Second Generation: 2004.5-2005 (LLY) 30 04-03-2006 09:59 AM
won't run over 2000 rpms pyj Duramax Second Generation: 2004.5-2005 (LLY) 20 09-11-2005 08:04 PM


All times are GMT -4. The time now is 07:39 PM.


Shoutbox provided by vBShout v6.2.1 (Lite) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd. Runs best on HiVelocity Hosting.
© AutoGuide

SEO by vBSEO 3.6.0