normal idle rpm

[DMalone]

Hello all, i did a search and could not find a answer to this question. What is the normal rpm at idle. I do have the PS high idle controller but my truck seems to be idling to high when it is turned off. Just wanting to check, thanks.

 

[Evan A. Beck]

On the Ram, the Cummins should idle at 800, ±25 RPM. As a comparison, the motorhomes and heavy trucks I work on that have the ISB idle at 700-750.

 

[lschultz]

Seems like mine idles around that 800 +/-. Sometimes its around 900.

 

[roadranger]

How would you adjust the idle on an HO?

Or is this controlled by the ECM?

 

[cbconway]

This thread brings to mind a pet peave of mine:



Who was the joker who made the divisions on my tach & speedo 125 rpm and 1. 25 mph, not the 100 rpm and 1 mph which any sane person would expect?!!! It took me a while and a couple of double takes to realize that there are only four divisions every 5 mph, not the 5 I'd expected. On the tach it's the same story.



Was this only on my 98. 5 or are all Rams the same? I'd sure like to get my hands on that design engineer.



(Thanks. I needed that rant. )

 

[LSMITH]

Chuck, all of them are like that, and it is a justified rant IMO. I have not seen an 02 yet, but I would guess that they are the same as well.

 

[Mschevey]

The probably had an electrical engineer design this because it ties into the ECM. Digital electronics work on powers of 2 therfore 2,4,8,16, etc. with 8 being the main one used. They design person had to deal with a digital signal that was based on 8 and rather than put the thought into making the display for a normal person they took the standard spacing and devided by 8. Giving us gauges with 125 RPM and 1. 25 MPH as standard spacing.



Mike



Mechanical engineer, (therefore take stabs at electrical engineeres whenever posible. )

 

[THerman]

Originally posted by cbconway



Who was the joker who made the divisions on my tach & speedo 125 rpm and 1. 25 mph, not the 100 rpm and 1 mph which any sane person would expect?!!! It took me a while and a couple of double takes to realize that there are only four divisions every 5 mph, not the 5 I'd expected. On the tach it's the same story.



Was this only on my 98. 5 or are all Rams the same? I'd sure like to get my hands on that design engineer.



(Thanks. I needed that rant. ) [/B]

2001's are like that as well... .

And I feel it had to do more with the school that fool went to! I know this EE was tought to think about things before running wide open... . but then again I guess I really never learned that in school! I vaguely remember someone else suggesting that it was an administrative decision... . I would hope that would explain it... . Remind anyone of Dilbert?

 

[lschultz]

Mschevey you said it---rather than put the thought into making the display for a normal person! These people are in another world.