Archived low idle issue

[SHAKEDOWN]

While i was driving back from up north this weekend,i got stuck in a major traffic jam on I-75,i noticed that the IDLE RPM had gone

down from 850 RPM to 600-650 RPM ,also it seemed a little sluggish when pulling and carrying the 2800 lb camper on back w/

2500 lb enclosed trailer.



My truck is basically stock ,exhaust has been tweaked with a Dynomax bullet muffler 3" all the way from turbo to the tail pipe.

 

[Thomas]

What year truck?

 

[SHAKEDOWN]

1997 3500 CC CTD 5SPD/3:54 2WD

 

[zack_76401]

lift pump may be going south... . easy fix and only around 150 bucks.....

 

[SHAKEDOWN]

I checked the lift pump screen,it had alot of small particles of something black and hard,there was also some metalic particals .



Cleaned everything and reassembled the unit ,pumped the pump

lit the starter

and the Cummins Fired right up !



But idle rpm was still at 650 rpms.

Going to change the fuel filter tomorrow.

The last time the filter was changed( Dec 12,2002)

and the truck wasen't driven much during the winter.

.

Is there an easy way to check fuel pres ?

 

[illflem]

Don't ask me why but it's not unusual at all for the idle to drop, turn it back up. Check for loose linkage parts. http://dodgeram.org/tech/dsl/adjustments/2nd_Gen-Idle.htm



No really easy way to check FP on a 12 valve. You have to either drill and tap the injection pump inlet banjo bolt to a 1/8'' pipe port or buy an adaptor from the filter bleed screw to 1/8'' pipe from TST for $25.



The black you found in the filter is called Asphaltine, normal and present to some extent in all diesel fuel. http://www.baldwinfilter.com/engineer/94_14.html

 

[SHAKEDOWN]

Thank you !!!

But ,how do i turn the idle back up on a 12 valve?

I was under the impression that timing could be an issue?

Guess thats not that case???



What is the normal fuel pressure supposed to be ?



THANKS AGAIN FOR YOUR HELP

SCOTT

 

[SHAKEDOWN]

OK i went to the site you suggested and printed the info ,tomorrow i will try this procedure .

I guess i would still like to know why this happened ?



Thanks again

Scott

 

[Joe G.]

Scott,



I don't know why but every so often my idle gets a little low. An adjustment fixes it with no problem. Seems to be the nature of the beast.

 

[SHAKEDOWN]

I talked to a Cummins Tech yesterday @Cummins of MT. Clemens,Mich. (THATS LIKE GOING INTO GRATIOT AUTO SUPPLY FOR CUMMINS GOODIES)

He told me that its not uncommon for the bolt head to wear out on top, at the stop ,just readjust the idle to 900 rpms and everything should be OK.





Thanks Again Folks

SCOTT @SHAKEDOWN RACING MOPAR OR NO CAR/TRUCK



97 3500 CC 2WD/5SPD/3:54

AMSOIL-OILS AND FILTERS

 

[illflem]

Yep, most of the time you only need to turn the bolt an eighth of a turn to get the bolt head to a fresh spot and the idle back up.

 

[SHAKEDOWN]

Well last night between rain drops ,i turned the idle up .



No problem,just a little hard to get at !



Once i actually saw the screw,it was a sinch to tweak.

Adjusted the idle up to 900 ,SWEET





Thanks again for all the help

Scott

next i want to turn up some more HPs on the Cummins!!!