Misfire @ cold start (-35) on my truck

YukonTyler · January 16, 2013

2008 6.4, 50 000 km, oil changes every 6 000 km and fuel filters every 12 000 km. I am a gas tech and don't really play with diesels.

I don't drive my 6.4 too often - I commute with a little Toyota. The last couple times I cold start it has been very cold (-35) and I have found a wandering idle until it starts to get up to temp.

At operating temp I have started to hear a slight noise - it sounds like a very soft fuel knock when under load. With engine speed up but no throttle (downhill) I do not have the slight knock. No knock at idle.

Today was warm so no misfire @ start up, but I brought it to the shop to scan. No check engine light.

P0266 CMDTC, low contribution #2 - shows @ fuel temp of -1, ambient temp of -36, run time of 5 minutes

Power balance is smooth. No misfire at operating temp. No black smoke (DPF delete running @ stock power levels). Oil level is holding at normal after 5000 km on this change. Short term trims are all either 0 or +1 except for #2 which is @ ~12 to 13.

Diesel techs here say it needs an injector. Seems pretty logical to me. If this thing is dropping extra fuel I am going to pull my glow plug and have a look at that, too. I will also look at rockers while I have the valve cover off.

Anything else I should be doing here? I would much prefer to catch issues like this early instead of getting into the business of melting pistons.