Jump to content
  • Welcome To Mopar1973Man.Com

    We can see that your guest and been lurking about. When you register on the Mopar1973Man.Com site you'll be able to interact with all the other members. This is the most friendliest Cummins forum you'll ever join. Take the time right now and  REGISTER  on the Mopar1973Man.Com this will open up many more options and functions on the website. Everyone is very friendly and helpful just ask questions and everyone will help you out the best they can. 

Sign in to follow this  
Dodgeih

3 cylinder high idle intermittently switching to 6

Recommended Posts

So it finally got cold enough to kick on the 3 cylinder high idle. After it runs for about 5 minutes I noticed that it intermittently switches to 6 cylinder high idle. I've had high idle for 3 years and this has never happened. When it does it it only does it for a second or less then it goes right back to 3 cylinder. Once it starts it does it 5-10 times per minute. I have searched on many forums with no findings of similar symptoms. Wondering if anyone has any idea on possible causes or has seen any threads with info on the topic.I'm going to attach a data log from quadzilla. It happened multiple times here 

3cylhi.csv

Here's a video, can slightly hear it

Hi.mp4

Share this post


Link to post
Share on other sites

The truck is smart enough to know if the truck is struggling to keep 1200 rpm in 3 cyl mode and it will kick out of 3 cyl into 6 cyl.  

 

This happens to me when the truck is cold cold and the vgt is in warmup mode.

Share this post


Link to post
Share on other sites

It has never done it before(although has been overhauled and new injectors since last winter) and its only a blip... Also only does it after starting to gain temp and run well not right off the bat when it's struggling... Did you happen to watch the video @Me78569

Share this post


Link to post
Share on other sites

Alternator loading? My does off and on where the grid heater hit and it stuggles to keep going against the exhaust brake. So I'll start out on 6 cylinder and flip over to 3 cylinder later. Or start on 3 cylinder and wait 5 minutes and the add exhaust brake. 

Share this post


Link to post
Share on other sites

My truck did this Christmas Eve morning as it was -11 F that morning when I started it to leave Colorado. It fired and shortly after as I walked back into the house it went to 3cyl it was like the anti-stall kicked in...quick rev on all six cylinders to keep it running and back to normal and 3cyl warmup. 

  • Like 1

Share this post


Link to post
Share on other sites
12 minutes ago, Mopar1973Man said:

If you watch you'll see the grid heater kick in about the same time the engine struggles and bounces out of 3 cylinder mode and revs back up on 6 cylinder mode.

That's exactly what I figured happened. 

Share this post


Link to post
Share on other sites
1 hour ago, Mopar1973Man said:

If you watch you'll see the grid heater kick in about the same time the engine struggles and bounces out of 3 cylinder mode and revs back up on 6 cylinder mode.

This is not the case. It will do it only after running just fine on 3 cylinder for 3-5 minutes, then is random, not in concert with grid heater cycle

2 hours ago, Me78569 said:

Its only a blip of a cylinder coming online.  

Exactly, you can hear it in the video I posted.. It only does it for less than a second

Share this post


Link to post
Share on other sites

I've seen where Quadzilla flops timing enough that 3 cylinder mode is running on 1, 2, and 3 cylinders. Remove the Quadzilla and it goes back to 4, 5, and 6 cylinders for 3 cylinder. Don't know why but it does switch it.

Share this post


Link to post
Share on other sites

you know what it is, it's the check in place to decide to fuel or not,  If rpms are above 1200 the quadzilla may trigger.fueling.  this is in place to allow timing adjustment nad fueling adjustment for trucks with Fly by wire CC.  


I can fix it if it is a big enough issue to warrant.

 

  • Like 1

Share this post


Link to post
Share on other sites
6 hours ago, Me78569 said:

you know what it is, it's the check in place to decide to fuel or not,  If rpms are above 1200 the quadzilla may trigger.fueling.  this is in place to allow timing adjustment nad fueling adjustment for trucks with Fly by wire CC.  


I can fix it if it is a big enough issue to warrant.

 

Honestly if it isn't going to hurt anything or runaway I don't care. Just was nervous could be vp,ecm, or injector issue

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Sign in to follow this  

×
×
  • Create New...