Idle speed

[Unreal Summit]

Drove my truck this morning and just happened to look at the idle speed when I got to work. It was at 822-825. The coolant temp had gotten hot enough to open the tstat. However at the time my temps were showing 180ish. So would this be a reason why it's idling a little higher than normal?  Idk why i pay so much attention to my gauges but I guess it's a good and bad thing 😆

[Mopar1973Man]

2 hours ago, Unreal Summit said:

Drove my truck this morning and just happened to look at the idle speed when I got to work. It was at 822-825. The coolant temp had gotten hot enough to open the tstat. However at the time my temps were showing 180ish. So would this be a reason why it's idling a little higher than normal?  Idk why i pay so much attention to my gauges but I guess it's a good and bad thing 😆

 

Ok, high idle after being fully warm is typically an issue with injectors popping too low. Do me a favor and check again. If idling and the idling is high like that watch the engine load if it at ZERO the injectors are done. What I mean is the pop pressure is so low the ECM is attempting to cut fuel to keep idle at 800 RPM but since the Engine load bottomed out it will idle high. 

 

SECRET: This is why when I had my 7 x 0.010 injectors built I opted for the pop pressure to be set at 320 bar it will extend the life span of the injector. As the pop pressure falls below the 293 bar which is minimum pop pressure as state by the Dodge FSM the Engine Load will continue to fall by the time its around 270-280 bar the engine load will bottom out. 

 

Coolant temps in the cold up here I will run down the pavement at 195°F but come to a stop and idle for 1 minute mine will drop in the 180 range quickly with the heater running. 

 

SECRET: If you unplugged the ECT sensor and had a proper range rheostat and increased the resistance so the temperature dropped back to near -40*F it will increase idle speed. Note this start down around below +60°F coolant temp if I remember correctly. Yup, I've played with the sensors and values quite a bit.

[Unreal Summit]

Engine load was 4-7%  ducky 7x.09 maybe 2 years old.   

 

Also idk if it's related or not but if I let my truck sit all night and start it the next day it will die when I pull it into gear unless I let it warm up for a while when it's cold outside.  I can get around this by starting the truck and immediately putting it into gear.  Triple disc torque converter

[Mopar1973Man]

7 minutes ago, Unreal Summit said:

Engine load was 4-7%  ducky 7x.09 maybe 2 years old.   

 

Getting marginal. I'm in the realm now with my 7 x 0.010 with my injectors. 

 

9 minutes ago, Unreal Summit said:

Also idk if it's related or not but if I let my truck sit all night and start it the next day it will die when I pull it into gear unless I let it warm up for a while when it's cold outside.  I can get around this by starting the truck and immediately putting it into gear.  Triple disc torque converter

 

Torque converter is too tight. When the ATF is cold the viscosity is higher of course. So when you start it up and drop into gear the torque grabs that cold fluid and stalls. I've seen this with several different members like @pepsi71ocean is the first off the top of my head that pops up that had similar issues with low stall converter install. 

[Unreal Summit]

I really thought I would get more life out of these injectors not a lot of miles. I think I'll go with @dieselautopower 7*10 next time. Might try the higher pop pressure too. 

 

Guess that's just something I will live with on the low stall that makes sense for sure! 

 

Thank you for you help. I knew something was up. I'll keep driving until it drops more. 

[Mopar1973Man]

Just heads up most injector builders will set the pop pressure at 300 to 305 bar. The minimum is 293 bar (4250 psi). I've seen injectors drop 20 bar in less than 20k miles. Remember stock is 310 bar (4500 psi).

 

320 bar is 4641 psi. Even in cold weather starts easy.

[Unreal Summit]

Understood.  I bought these in 2020. Maybe 30,000 miles. Should I request higher pop like 320 or just go with 310?

[Mopar1973Man]

I would suggest 315 bar for 7 x 0.009 injectors.

[Unreal Summit]

Thank you!

[Max Tune]

5 hours ago, Unreal Summit said:

Engine load was 4-7%  ducky 7x.09 maybe 2 years old.   

 

Also idk if it's related or not but if I let my truck sit all night and start it the next day it will die when I pull it into gear unless I let it warm up for a while when it's cold outside.  I can get around this by starting the truck and immediately putting it into gear.  Triple disc torque converter

I have the same issue with triple disc converter in cold weather. I start truck and put trans in neutral to flow fluid and get it moving. Another trick is hold idle about 1000-1200 and put in gear. 

 

I'm also due for injectors as I'm getting  some haze and fully warmed only about 2% load.

 

 

P.S. to moparman, I know you've said it before but I don't remember.  What should  idle load be at fully warmed and good injectors?

Edited January 28, 2023 by Max Tune

[Unreal Summit]

Sooo now my radiator is leaking. What's a good buy for one that y'all have a good experience with 

[dieselautopower]

Dying when you put it in gear is related from too high of pop pressure and bigger injectors.  Automatics are more susceptible to the stalling.

[Max Tune]

6 hours ago, dieselautopower said:

Dying when you put it in gear is related from too high of pop pressure and bigger injectors.  Automatics are more susceptible to the stalling.

My injectors seem to be pretty well shot. Engine load fully warmed at idle is +/- 2%. The only time truck dies when put in gear is when outside temps are below freezing. If I put it in neutral for a while or hold idle up a bit, it will stumble but not die. Once warmed up or during summer, there is no issue at all.

[Mopar1973Man]

Yup getting down to the bitter ends. 

[Hutch24v]

22 hours ago, dieselautopower said:

Dying when you put it in gear is related from too high of pop pressure and bigger injectors.  Automatics are more susceptible to the stalling

This happened to me all the time while the truck was cold, especially shifting into Drive (Reverse was ok). After it warmed up for 5+ minutes it wouldn't stall. Then after I had my trans rebuilt the condition went away but there is a slight engine microsecond hesitation shifting into R or D while the engine is not at full operating temp.

 

 

On 1/28/2023 at 10:33 AM, Mopar1973Man said:

I would suggest 315 bar for 7 x 0.009 injectors.

I installed new DAP 7x.009 injectors a few months ago and they were set to 311 Bar.  

[Mopar1973Man]

28 minutes ago, Hutch24v said:

I installed new DAP 7x.009 injectors a few months ago and they were set to 311 Bar.  

 

Just a heads up I've had a few members have issues later on after the injectors were built and have the pop pressure fail out. Like the one that sticks in my head was @pepsi71ocean had a set of 100 HP injectors and had then built and after 28k miles roughly the pop pressure dropped to 280 bar and created part of his stalling issues. Injectors will settle over time and drop pop pressure some more than others. 

[dieselautopower]

It can be a narrow window and every truck may have a different variance.

 

I talked with someone years ago.  He had stock Bosch  RV275 at standard pressure and a tight  torque converter which  lead to stalls in reverse when cold