How to Adjust Idle RPM? - Dodge Cummins Diesel Forum

89-93 Powertrain Discussion of components that are directly involved in the power production and all that is needed to get and keep the truck moving . Engine , Transmission Ect...NO ADVERTISING

 
LinkBack Thread Tools Display Modes
post #1 of 11 (permalink) Old 06-27-2010, 10:56 PM Thread Starter
Cummins Nut
 
ARbowhunter7's Avatar
 
Join Date: Mar 2010
Posts: 312
Thanks: 7
Thanked 26 Times in 22 Posts
iTrader Score: 1 reviews
How to Adjust Idle RPM?

First, my truck idles MUCH too high. I don't have a tach yet, but it sounds REALLY high compared to other trucks. I am also seeing other tendencies that would indicate a higher idle than normal. First, when I crank it up, even when cold, it fires up faster than any truck I've ever owned...less than half a turn of the starter and it's running. Seems like this could be a sign, also, there is a big jolt/shock when switching into gear from Park or Neutral.

I have read about a screw to adjust idle, and I imagine I could find out where it is, but I'm really looking for advice from you guys about adjusting it. How much adjustment drops 100 rpm, etc...and tips or pointers you could give me would be great. Thanks.


1998 12V 3500 4x4...You know what it is
ARbowhunter7 is offline  
Sponsored Links
Advertisement
 
post #2 of 11 (permalink) Old 06-28-2010, 10:41 AM
Diesel Head
 
Left out in the cold's Avatar
 
Join Date: Jan 2009
Posts: 2,629
Thanks: 86
Thanked 231 Times in 192 Posts
iTrader Score: 0 reviews
A fast start is the sign of a good engine. Looking at the injection pump from the finder side you see a long screw with a lock nut that the throttle arm hits at full throttle. That is the full throttle stop. On the back side (engine side) of the pump is an identical screw, that is the idle screw. Loosen the lock nut and back the screw out until you reach 750RPM. Then lock the nut.
Left out in the cold is offline  
The Following User Says Thank You to Left out in the cold For This Useful Post:
Cummins250 (03-06-2011)
post #3 of 11 (permalink) Old 06-29-2010, 04:57 PM
Diesel Freak
 
powerbrake's Avatar
 
Join Date: Feb 2009
Location: charleston west by god
Posts: 555
Thanks: 87
Thanked 107 Times in 59 Posts
iTrader Score: 0 reviews
Quote:
Originally Posted by Left out in the cold View Post
A fast start is the sign of a good engine. Looking at the injection pump from the finder side you see a long screw with a lock nut that the throttle arm hits at full throttle. That is the full throttle stop. On the back side (engine side) of the pump is an identical screw, that is the idle screw. Loosen the lock nut and back the screw out until you reach 750RPM. Then lock the nut.
what you said, yes indeed. unless the dern screw want to be a pain. mine was so i took a dremmel tool and started grinding away at the end of the screw until i got the rpm i wanted

92 4x4, fuel screw turned in all the way, starwheel dropped to the bottom, 40 hp injectors, machined pin, detroit locker lets me smoke 'em evenly. auto meter pyro.
God Bless Our Country and Damn The Goverment
powerbrake is offline  
post #4 of 11 (permalink) Old 06-29-2010, 05:40 PM
Diesel Head
 
Left out in the cold's Avatar
 
Join Date: Jan 2009
Posts: 2,629
Thanks: 86
Thanked 231 Times in 192 Posts
iTrader Score: 0 reviews
Quote:
Originally Posted by powerbrake View Post
what you said, yes indeed. unless the dern screw want to be a pain. mine was so i took a dremmel tool and started grinding away at the end of the screw until i got the rpm i wanted
Your not fooling anyone. We know you and power tools.
Left out in the cold is offline  
post #5 of 11 (permalink) Old 06-29-2010, 05:42 PM
CumminsT92
Guest
 
Posts: n/a
mine was easy to adjust. took about 5 min to find 700rpm. but it wasn't hard at all.
post #6 of 11 (permalink) Old 06-29-2010, 05:52 PM
Diesel Freak
 
powerbrake's Avatar
 
Join Date: Feb 2009
Location: charleston west by god
Posts: 555
Thanks: 87
Thanked 107 Times in 59 Posts
iTrader Score: 0 reviews
Quote:
Originally Posted by Left out in the cold View Post
Your not fooling anyone. We know you and power tools.
more power

92 4x4, fuel screw turned in all the way, starwheel dropped to the bottom, 40 hp injectors, machined pin, detroit locker lets me smoke 'em evenly. auto meter pyro.
God Bless Our Country and Damn The Goverment
powerbrake is offline  
post #7 of 11 (permalink) Old 07-04-2010, 11:50 PM
Newbie
 
Join Date: Jan 2010
Posts: 7
Thanks: 0
Thanked 0 Times in 0 Posts
iTrader Score: 0 reviews
I used my pliers and bent the tab just a hair. worked perfect.

1994 Chevrolet 1 ton flatbed, with 12 valve cummins. nv4500, advanced adapters bellhousing. oversized flywheel & 13" clutch. Pillar mounted Isspro pyro and boost gauges. 3" straight exhaust.
plcnut is offline  
post #8 of 11 (permalink) Old 07-05-2010, 10:59 AM
Diesel Freak
 
tiny2085's Avatar
 
Join Date: Oct 2008
Location: Erda, UT
Posts: 634
Thanks: 25
Thanked 44 Times in 38 Posts
iTrader Score: 0 reviews
I also don't have a tach, an after adjusting my power screw the truck idled high enough to be a pain at stop lights. I just used my ear, listened for a smooth quite idle, made sure the oil pressure was still good and called it a day. Make sure and put it in drive after you adjust it to make sure it's still smooth under a load with the A/C on.

1997 3500 SLT 109K DPS 3PC/Banks BIG HEAD/Banks EXH. Brake/Banks Trans Brake/Banks 4" TBE/Banks pyro,boost,trans/Prodigy P2 trailer brake
tiny2085 is offline  
post #9 of 11 (permalink) Old 03-06-2011, 11:35 AM
Newbie
 
Cummins250's Avatar
 
Join Date: Feb 2011
Location: Oklahoma
Posts: 3
Thanks: 3
Thanked 0 Times in 0 Posts
iTrader Score: 0 reviews
Quote:
Originally Posted by Left out in the cold View Post
A fast start is the sign of a good engine. Looking at the injection pump from the finder side you see a long screw with a lock nut that the throttle arm hits at full throttle. That is the full throttle stop. On the back side (engine side) of the pump is an identical screw, that is the idle screw. Loosen the lock nut and back the screw out until you reach 750RPM. Then lock the nut.
is there anyway you guys could post a pic i must be blind b/c im not seein it thanks to all !
Cummins250 is offline  
post #10 of 11 (permalink) Old 03-06-2011, 12:02 PM
Moderator
 
9297oldram's Avatar
 
Join Date: Sep 2010
Location: Huntington In.
Posts: 12,930
Thanks: 377
Thanked 1,590 Times in 1,469 Posts
iTrader Score: 0 reviews
Look at the opposite end of the arm that the throttle linkage fastens to, it's just a threaded bolt with a lock nut that's hard to get to.

92 D250 custom made bed, 190 inj., 16cm , electric cooling fan, 2nd gen air horn, 5spd., Dana 61 3.31 gears, 1 stage W/M set up

97 2500 4X4 auto DDP 40 HP injectors, no 8 fuel plate, homemade 3" intake horn, BD converter, BHAF, electric cooling fan
9297oldram is online now  
The Following User Says Thank You to 9297oldram For This Useful Post:
Cummins250 (03-06-2011)
post #11 of 11 (permalink) Old 03-06-2011, 09:43 PM
Newbie
 
Cummins250's Avatar
 
Join Date: Feb 2011
Location: Oklahoma
Posts: 3
Thanks: 3
Thanked 0 Times in 0 Posts
iTrader Score: 0 reviews
Quote:
Originally Posted by 9297oldram View Post
Look at the opposite end of the arm that the throttle linkage fastens to, it's just a threaded bolt with a lock nut that's hard to get to.
oh duh right in front of me haha thanks guys appreciate it !!
Cummins250 is offline  
Sponsored Links
Advertisement
 
Closed Thread

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Dodge Cummins Diesel Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

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:
OR

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
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



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

 
For the best viewing experience please update your browser to Google Chrome