2008 5.7l Hemi

[spellbound37042]

I have a unusual situation with a vehicle that I have never encountered before and have replaced many parts to see what is going on, I have a 2008 dodge Durango, my 2008 dodge Durango in cold temperature 45 degrees and below when you first start it up for the first time of the day everyday the engine will spit and sputter and make a popping sound in the intake system sounds like a back fire and the check engine light flashes and the code is multiple misfire but not a certain cylinder misfire, when the engine warms up for 3 or 4 minutes the missing and sputtering and popping stops and the engine runs great for the rest of the day no matter how many times I stop and start it,but if the temperature is around 50 degrees or warmer outside the vehicle will start up and run with no issues even if it’s the first start of the day,the engine 5.7l hemi mds, all the sensors have been replaced with original mopar parts (crank,cam, IAT, MAP etc.) even the heads and all timing components were all replaced new and the top of the pistons cleaned to a shine to make sure no carbon but after all this work still have this popping and miss firing issue on start ups at 45 degree’s, Ever heard of this issue?

 

[jws123]

Fuel pump check pressure also in the morning before you fire it up cycle the cey 3-4 times then start see if it runs better.

 

[rzr6-4]

Might be overly simple but spark plugs may be an easy fix. If they are fouled up or if the gap is off, they might not be putting out a good spark. When the engine is warm, even if just a little, its easier to get the fuel to ignite but cold it needs all the help it can get. Old plugs may just not have enough spark on a cold start.

 

[spellbound37042]

To let everyone know , the spark plugs are new and gapped properly the old ones did the same thing too so I doubt it’s the plugs.