hi new here iv got a dodge diesel has had a miss for three yrs now check engine light nothing light miss does it once in a while sometimes missis good bit then maybe not again for long while pulled injectiors had them bench checked were fine check fuel preassure had computer checked every thing was fine new fuel filter no change no smoke runs great other than this miss that comes and goes bought truck new 120,000 miles on it got a edge chip been on it since new any ideas would be helpful thanks.

 

a miss would be injectors or connector tubes to the injectors or the wiring to the injectors.

that is really the only thing that can cause a miss in a common rail.

your injection pump does not do individual cylinders like a vp44 or p7100 or VE. it merely just pressurizes the rail and the injectors and ECM have all of the firing control from there.

suppose it could be low compression in one of the cylinders as well, but very unlikely.

might just have a loose wire somewhere.

 

I talked to a guy once said they had one doing same thing they fond enjectior wireing harness under valve cover had a short once in a while when it go jus right it would miss is this possible that the heat would break the wires down and now and then it would break down im in east Orlando fl if I could find a good person that new what he was doing id let him look at it I no harness under valve cover is 400.00 at dodge thanks ill try to look at what you said

 

yeah like I said, those parts are really the only thing that could cause a miss... the injectors are electronically controlled to open and close. the fuel injection even is what causes the fuel to detonate inside the cylinder. timing is controlled electronically. amount of fuel and injector open/close is electronically controlled.. fuel supply is just 1 pump that handles all cylinders and it supplies fuel at very high pressure held back by the injectors until the ECM tells the injector to fire.

wire short or loose, or bad injector are your most likely causes. good luck with it!