12 Valve 2nd Gen Dodge Cummins 94-98 Discussion of 12 Valve 5.9 Liter Dodge Cummins Diesels with P7100 Injection Pumps

"Chugging" question

Thread Tools
 
Search this Thread
 
  #1  
Old 06-03-2012, 06:59 PM
cumminstothefloor's Avatar
Diesel Fan
Thread Starter
Join Date: May 2012
Location: New Jersey
Posts: 73
Likes: 0
Received 1 Like on 1 Post
Default "Chugging" question

My truck has a slight "Chug" to it when accelerating, typically lower rpm's. It sounds almost like a slight miss. I checked the timing, which was dead on, and adjusted valve lash, which was a little tight but didn't fix the problem. I also tried cracking each injector line while it was running and listened for a drop in rpm's and cylinder #1 had almost no change. Could this possibly be a weak/bad injector? I don't notice the chugging if I really get on it which is weird. any input?
Also, I don't know the brand of the injectors, would it be an issue to replace one injector with a different brand? Is there any numbers stamped in them to help identify?
Thank you everyone.

You can see the mods in my signature.

---AutoMerged DoublePost---

Anyone ever hear of this?
 

Last edited by cumminstothefloor; 06-03-2012 at 06:59 PM. Reason: Automerged Doublepost
  #2  
Old 06-03-2012, 10:44 PM
coreywarren's Avatar
Newbie
Join Date: Jun 2012
Posts: 7
Likes: 0
Received 0 Likes on 0 Posts
Default

I have the same problem going on. Were you able to fix the problem? I just hooked a fuel pressure gauge up today and it's only reading like 11psi at idle, 20 max at 55mph and let off the gas pedal. So I'm thinking it's the lift pump
 
  #3  
Old 06-04-2012, 12:31 PM
Smarty=Cummins's Avatar
Diesel Enthusiast
Join Date: Feb 2011
Location: DuBois NE
Posts: 292
Received 5 Likes on 5 Posts
Default

This happen to my buddy's truck n we took the injectors out and #2 n #6 was bad it was only spraying out of one hole. The rest of the holes was all plugged up with stuff.
 
  #4  
Old 06-04-2012, 01:20 PM
coreywarren's Avatar
Newbie
Join Date: Jun 2012
Posts: 7
Likes: 0
Received 0 Likes on 0 Posts
Default

Did you end up replacing them or just cleaning them out?
 
  #5  
Old 06-04-2012, 01:58 PM
South Tx Coal Roller's Avatar
Diesel Enthusiast
Join Date: Jun 2011
Location: Wharton Tx
Posts: 250
Received 14 Likes on 12 Posts
Default

I'm thinking it could be an injector. Do you have a shop anywhere around you that can pop test them?
 
  #6  
Old 06-04-2012, 02:04 PM
coreywarren's Avatar
Newbie
Join Date: Jun 2012
Posts: 7
Likes: 0
Received 0 Likes on 0 Posts
Default

No not that I know of. Would the bad injector cause low fuel pressure though at the pump?
 
  #7  
Old 06-04-2012, 02:35 PM
South Tx Coal Roller's Avatar
Diesel Enthusiast
Join Date: Jun 2011
Location: Wharton Tx
Posts: 250
Received 14 Likes on 12 Posts
Default

Originally Posted by coreywarren
No not that I know of. Would the bad injector cause low fuel pressure though at the pump?
That could be the lift pump or overflow valve. How many miles are on the truck?
 
  #8  
Old 06-04-2012, 02:38 PM
coreywarren's Avatar
Newbie
Join Date: Jun 2012
Posts: 7
Likes: 0
Received 0 Likes on 0 Posts
Default

It has 148k an I did the return hose check for the overflow and pressure stayed the same only would move 1 or 2 psi maybe. So I'm thinking the lift pump
 
  #9  
Old 06-04-2012, 02:56 PM
South Tx Coal Roller's Avatar
Diesel Enthusiast
Join Date: Jun 2011
Location: Wharton Tx
Posts: 250
Received 14 Likes on 12 Posts
Default

There is also a fuel heater on the side of the block that has a metal screen that can become clogged up.
 
  #10  
Old 06-04-2012, 03:15 PM
coreywarren's Avatar
Newbie
Join Date: Jun 2012
Posts: 7
Likes: 0
Received 0 Likes on 0 Posts
Default

Yeah Ive taken that off cleane te screen wasn't very dirty. And I also replaced the rubber elbow that goes from the lift pump to the heater. That was cracked and leaking pretty good.
I think I'm gonna take the fuel heater right out, I've Hurd that your better off without it
 


Quick Reply: "Chugging" question



All times are GMT -5. The time now is 09:30 PM.