Aside from the obvious injector etc explanations it could be air in the fuel lines, a map sensor, or bad timing. A repitable shop should be able to put a live scanner on it to see what everything is doing at any given time. They can then pinpoint, to an extent, what the problem is.

 

Took my truck to a Freightliner dealer who is also a CTD enthusiast and they also use the same engine in their 3-5ton rigs with cummins programing instead of Dodge. Here is the story, I noticed first a significant vibration in the exhaust system at idle only, then after a number of trips to my exhaust guy, it was finally determined that the vibe was not due to the exhaust system and it was originating from a vibe caused aty the engine. Motor mounts were good, did not see any significant vibes at the engine. Over next few days vibes getting worse and loosing power. Took it to the freightliner guy and he placed his hand on the engine and in two seconds he said "You have an injector miss" I said "you must have seen this before"?
He said this is quite common, first check fuel system for restriction, blockage (fuel filter) check for water in fuel, then flush 1L of 2stroke oil through with next tank of fuel, if symptoms do no clear up then you have a fouled injector.

Just a point of interest, has anyone just re-set their computer and checked if symptoms persist?

 

I have no codes and the problem didn't begin til after the RV275's were installed. My LP did die recently and I installed a FASS system, but not before the VP44 was subjected to <5psi a few times. But again, the miss at warm idle was happening before the LP went out. However, this is the 2nd time the LP went out. The PO had just replaced the LP when I bought the truck (this one didn't last more than 15k) so the VP44 may have already seen some unncessary wear. This is why I am thinking the new injectors just uncovered an existing problem. don't know for sure... just counting the days til the VP44 goes out and I'll replace it with an HRVP44. maybe, just maybe i'll get lucky enough to have that fix it (as if spending $1700 is lucky). Still... it sure is nice not to have truck payments and I'd like to keep it that way for as long as possible, so if I have to drop a few $$ here and there to keep it running, so be it.

what do you mean reset the computer?

 

Unplug battery terminals let stand unplugged for half hour and then connect and start. I was told this will clear codes and restore factory settings. THis is my first diesel and I am trying to learn as much as I can. But from what I have learned so far, the cummins is not the issue, it is the Dodge programming that is creating all the havoc with these engines.

I have the stock injectors but the injector miss has just recently become more aparent due to a lack of power and a significant vibration in the ingine at all RPMs. I can even feel the vibration up through the foot feed.

I am concerned as I know of atleast three trucks that blew the engines and the dealer said the engine was dusted. All experienced similar symptoms as mine but further investigation into the engines found that there was excess wear on two of the six cylinders. If the engines were dusted then similar wear should be evident on all cyls. Also only one of these had been run on a box the other two were stock from day one. Fouled injectors causing piston wash sounds more believable than dusted engine syndrome.

 

I have found this happening to my truck about 2 months ago and was curious to what was going on. All of your experiences are intertwined with mine in a round-a-bout way. So In a nutshell what is the plan of attack to try and fix this problem. Take it to a dealer, unhook the battery cables? Im glad im a part of this site otherwise i would be pulling my hair out!!

 

Hey, FWIW,

I'm with you guys, have the same issue. Took it to Cummins, they can't find the problem. It would be helpful if the miss wasn't so erratic. I have replaced
the cam and crank position sensors, map, iat. Reset the apps, blah, blah, blah.... I just live with it, I don't like it, but until something breaks???

I am on my 4th LP, with 225k on the clock. Hope that we can find a solution.

Not much help here, strength in numbers....

Jeff

 

Taking my truck in to the dealer on Monday morning to have the injectors, pump pressure and ECM checked out. I will let you know what I find out.

 

so what did you find out?

 

Just as I expected.......They said there was nothing wrong.....I asked the kid behingd the service counter "how did you check the injectors"? he rattled off about engine road tested cold, road tested warm, could not duplicate customer complaint...BLAH, BLAH, BLAH. I said road test????? then another moreseasoned BS'er from behind the counter said they would have done an injector kill test. I asked why that is not indicated on the work order.....no answer...just as I expected. when I get a chance I'm going in to Cummins to see if they can tell me anything. But to the credit of the dealership, they did find some issues in my suspension (drag link) and drive train (two front U-joints) and a rear wheel seal which were covered under warranty. Also had front breaks done as there was only 10% remaining. So I guess it was worth the two days in the shop.

 

hmmm.. good thread. i'll be watching this one. bd's injection installation states that some customers have complained about rought idles after installing injections but find no problems.

 

Ok I had that miss problem for over a year sorry to tell ya guys but the fix was a new VP44.

 

I wouldn't say thats the only fix, as I had it both before and after new nozzles (pop tested prior to install) as well as new IPs.

I just installed a Smarty on my truck, and although it didn't completely eliminate it, it certainly made it much smoother than before. I also have a P0222 code, idle validation signals both low. Probably has something to do with it.

 

I have the same problem, taking it to a shop tomarrow. ill keep u posted..

 

I have the same problem as yall but mine is worse. it happens cold, hot when ever. It just cuts out. At idle, revved up, it is not picky. It cuts out so bad that the truck shuts off sometimes. But every time bump the key and vroom cranks right up. This VP is 1 yr old and has had an airdog on it the whole time with good pressure.

 

I've never experienced it but I've read about incorrectly installing the vp's gear would cause bad timing, irradic idle. I don't know if it is even possible to do since I have not had to change any of my injection pumps yet, but I read that if the gear is installed at a wrong clocking (gear is too far clockwise or counter-clockwise compared to where it was when removed) the injection pump is 'firing' the injector out of time.
Just a thought since the original post said problem started after vp install.