Motor missfire?

[DWestfall]

What could cause my truck to sound as if it were missing. Not all the time, but sometimes under these conditions: It does it at low idle, high idle, warm, cold. Again not all the time. Today I was out of my truck for about 10 minutes and left it running in N. Heard it miss a few times on high idle. When I went to leave, upon acceleration it dumped a bunch of white smoke. Quad has been disconnected completely for 3 months. 1 month ago had lift pump replaced with in tank unit. Has been missing now for about 3 months. Ever since this happened: http://www.tdr1.com/forums/showthread.php?t=142875 I never really noticed it before this, only when Quad was plugged in. Even dealer commented on this last summer. Said my truck was "weird" by the way it idled. What do you think? Injector, bent valve? It goes in to dealer Wednesday morning. I have 99,140 miles. I just barely made it. My last two tanks, MPG has been terrible. Did oil analysis last week with oil change no abnormalties it said. Although it said, Fuel-0. 5% Soot-<. 1%. Normal?

 

[DWestfall]

Come on, somebody!

 

[PSime]

One word - Injector

 

[JStieger]

If your dealer said it idled "weird" with nothing else to offer then I would avoid them like the plague! That being said, I experienced the same symptons as you before.



The first time was when I ran a TST PMCR box before the one I currently have now. Read about it here: TST problems



The second time was when my injectors carboned up due to my driving habits detailed in this thread



I have since changed my driving habits to working the truck a lot harder!

 

[PSime]

To elaborate a little more on my one word reply, more then likely you have as JStieger had a "dirty" injector/s. If you take it to a GOOD (key work good) dealer they will plug into it and tell you what cylinder/s has the missfire. A quick easy fix is to run injector cleaner to see if it clears up. If not you may have to replace injectors. At the dealer I work at we have replaced injectors for the same exact reasons you are stating. (oh and it fixed it to) I am not going to guarentee this is the problem but there is a 95% chance that it is. Good Luck!

 

[JStieger]

When I first brought the truck in, the first thing the diesel tech said was "injectors". He said it didn't matter if it was a semi, old Dodge, new Dodge, Ford, etc - it was the classic symptoms of injectors as PSime said. Nevertheless, he still went through the DRB3 stuff as standard protocol and it didn't show diddly, whether through its testing programs or while I was driving consistently reproducing the miss and stumble. I even ran boat loads of injector cleaner through my truck and that didn't help.



The pictures in the thread I referenced above do not show the carboning at its worst. There were large flakes coming off the nozzle tips and there were carbon chunks inside the injector too.



Bottom line is that one has to keep a large trailer hooked up to these trucks to really work them and get them hot!

 

[DWestfall]

I tow about 4k all the time at 70-73MPH, which is nothing, so I am not babying the truck either. I would say that 90k is all towing. I just fueled up and went 467 miles and put in 35. 9 gallons leaving me with a disappointing 13 MPG. I usually get 14. 5-16. 7 towing. Could injectors cause this? Air filter is fairly new. Fuel filter last week. Hope they can figure it out.

 

[CSwitzer]

motor missfire/white smoke

I have a 2004. 5 ram3500 srw and it used to miss all the time hot or cold, idle or under acceleration. I took it to the dealer several times,were they road tested it,brought it back and said there had to be air in the fuel system for it to miss and or backfire at idle and under moderate acceleration. The dealer finally gave me the offer, that they would pay for a fass 95 install to see if that would help. Since the install last spring, I have never heard or felt a miss or backfire again, unbelievable. I had once heard that some early 600's had these problems (missing/backfire) in colder climates, was also told that there could have been a code missing. But hard to say cause the fass cleared up everything on this one.

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04. 5 Ram3500 SRW/4. 10/FASS 95/Edge EZ/ATS arc intake/AFE stg2/4inch straight w/no kitty/BD-Xmonitor/16. 7 mpg in town Oo.

 

[Cattletrkr]

I had once heard that some early 600's had these problems (missing/backfire) in colder climates

That's interesting. When it's cold (subzero or nearly so) my truck runs like crap. I've described it to the dealer as a miss. Reflashed (18-007-34 I think) and injector tested, but nothing ever turned up. It's been over 50K since I've even thought about it. It still does it. Mine isn't at idle though, mine's at about 2500rpm workin' hard towing uphill. Just sounds rough and not as much power as it normally has. Oil analyses have shown no fuel in oil.



I've just been chalkin' it up as "one of those things". It's probably all in my head since I ain't blowed it up yet.

 

[CSwitzer]

Yep that sounds about right mine used to belch white smoke, and backfire fairly loud under throttle between about 1800 rpm's and 2500 r's. I used to live in a pretty cool climate on the WI-MN border.



04. 5 Ram3500 SRW QC/4. 10/FASS 95/Edge EZ/ATS Arc Intake/AFE Stg2/4inch stright pipe no kitty/BD-Xmonitor/16. 7mpg in town