Dodge Diesel - Diesel Truck Resource Forums

Dodge Diesel - Diesel Truck Resource Forums (https://www.dieseltruckresource.com/forums/)
-   12 Valve Engine and Drivetrain (https://www.dieseltruckresource.com/forums/12-valve-engine-drivetrain-100/)
-   -   low idle at startup (https://www.dieseltruckresource.com/forums/12-valve-engine-drivetrain-100/low-idle-startup-307470/)

Tank_66 10-28-2012 08:07 AM

low idle at startup
 
when I start up my 12 valve, it has a very low idle, but when it warms up the idle gradually increases, I've adjusted the idle, and it does the same thing if I have it set at 700rpm it will warm up and be around 800-900RPM. the lift pump is new, injection pump was rebuilt not long ago, and I've got 75hp ddp injectors.
an Ideas, or is this normal

joem 10-28-2012 10:57 AM

mine does that too, 400 rpm at cold start 600 warm. then back down to 400 if its over 110F I always figured it was the thick oil and less effecent of a cumbustion burn+ mechanical throttle without any electronic idle control

Tate 10-28-2012 11:37 AM

Back off the gov. springs a click, then readjust the idle.

gorms 10-28-2012 02:28 PM

Mine is the same way, regardless of "cold" starting temp, will be about 200 rpms less then warm engine idle. A few seconds with foot on the throttle gets it closer pretty quick.

Tmello401 11-09-2012 06:49 PM

same thing cold its about 400-500 and warm 600-750. Just is Cold, is normal ive come to realize.

jdwest 11-16-2012 03:13 PM

Seems most mechanically injected diesels do this...nature of the beast. No computer to compensate for a cold engine and cold start to advance more fuel.

eng208 11-23-2012 06:50 AM

My P pumped Cummins has always done this. Figure it is normal. I also have to apply a touch of throttle to get an immediate start, otherwise it turns over a couple of times like an older gas engine. The VE pumped Cummins had neither of these issues.

NE frmhnd 11-23-2012 10:06 AM


Originally Posted by eng208 (Post 3148302)
I also have to apply a touch of throttle to get an immediate start, otherwise it turns over a couple of times like an older gas engine. The VE pumped Cummins had neither of these issues.

Or new gas engines or new diesels. I can't tell you how often I get in a p-pumped or gas truck and touch the starter and sit there with a dead engine.

Diesel Dave2 11-23-2012 10:10 AM

My truck does the same when cold...I thought that was normal...I have a manual high idle cable for warm up ...

Tate 11-23-2012 06:23 PM


Originally Posted by eng208 (Post 3148302)
My P pumped Cummins has always done this. Figure it is normal. I also have to apply a touch of throttle to get an immediate start, otherwise it turns over a couple of times like an older gas engine. The VE pumped Cummins had neither of these issues.

Or adjust the governor springs and idle and it fires up immediately. Seems like a simple solution.

Tmello401 12-02-2012 07:03 PM


Originally Posted by Diesel Dave2 (Post 3148323)
My truck does the same when cold...I thought that was normal...I have a manual high idle cable for warm up ...

How and where did you get the cable/switch or if you made it how?

9812vram 12-04-2012 02:55 PM


Originally Posted by Tate (Post 3142061)
Back off the gov. springs a click, then readjust the idle.


Originally Posted by Tate (Post 3148385)
Or adjust the governor springs and idle and it fires up immediately. Seems like a simple solution.

X2

I've been down this road already, argued about it in another thread somewhere. Tate has the answer, and it is simple.

Chris W 01-23-2023 04:36 PM


Originally Posted by Tate (Post 3148385)
Or adjust the governor springs and idle and it fires up immediately. Seems like a simple solution.

Do you have a resource on how to do that?

texasprd 01-24-2023 09:18 AM

Tate hasn't been on since Dec 2014, according to his user info - and this thread died in 2012. Do you need a resource for adjusting the idle, or the governor springs? Do a google search for "p7100 pump adjust governor springs", or use the search facility on here to search this forum. This should come up in your search results...

Chris W 01-24-2023 09:22 AM


Originally Posted by texasprd (Post 3383204)
Tate hasn't been on since Dec 2014, according to his user info - and this thread died in 2012. Do you need a resource for adjusting the idle, or the governor springs? Do a google search for "p7100 pump adjust governor springs", or use the search facility on here to search this forum. This should come up in your search results...

So I did search for it but everyone is either replacing them or bench adjusting it, I’m not finding anything of adjusting them on the truck. It does it anytime it gets below 65 or so, but if I plug it in it doesn’t have much of a problem until it gets to teens.


All times are GMT -5. The time now is 07:24 PM.


© 2024 MH Sub I, LLC dba Internet Brands