2013 Cummins isx 15 runs very rich in cold temps

Hello everyone, I’ve been chasing a ghost with my truck for over a year. This truck was overhauled 250k ago (no idea what all was replaced, paperwork isn’t super in depth) it was also deleted supposedly in 2014. The truck is a 2013 Pete. This thing ran great ever since I got it. Last winter in Iowa we had a bad storm roll in over Christmas bringing -30 temps with it. I had my truck plugged in and fuel treated, however when I began to run again it was 40 degrees outside. Truck ran terrible. Found algae. After treating the truck and cleaning out the system and several filters later the algae was gone but the truck still ran like crap in the cold. It runs too rich. Causing it to stumble or blubber. Especially if the engine is below 170 degrees. Fast forward, the truck ran perfect all summer. However has an EGR delta pressure code which it doesn’t have an EGR. Fast forward again it’s now almost thanksgiving and the temps are dropping outside. Now it’s having troubles again. Smokes out all the mosquitoes in the neighborhood if I try to move the truck before it reaches operating temp. If I’m idled up all night the truck runs around 160 overnight so naturally it’s smoking blue/white out the stacks all night. It seems to only have this stumbling issue when it’s cold outside. I had it looked at, the fuel rail is getting proper pressure, no leaks, they said no air was getting sucked in. They did a cut out test, worked fine. Now that doesn’t show trims or rates of course but it appears the fuel system up to the fuel rail is just fine. They ran an overhead, didn’t do anything. There’s no other codes in the ecm besides EGR delta pressure. But no EGR. I ordered a new Barometric pressure sensor hoping that in some way maybe the dense cold air was causing that sensor to adjust my fuel trims. It’s a Hail Mary but I have zero idea where else to look. No shop has figured it out yet. I don’t want to go to the extent of all new injectors without evidence any of them are bad. I also don’t want to try and have a new tune installed it if that won’t help either. The guy I bought this truck from was a total #### head so who knows how he did any of the delete. He claimed the truck had the factory 500 Cummins tune. There is zero emissions on this truck. The entire system is gone. On occasion when you run down the road at 190 degree operating temp at about 1400-1500 rpm you can faintly feel the stumble. Ever so lightly but you feel it. I really think it’s somehow getting too much fuel.

 

I’m not disagreeing with you on that. However, it ran perfectly fine for almost 2 years since I bought it then this year it’s had the EGR code. Which wasn’t there previously. However, on the flip side, if someone flashed my ecm without me knowing then you’d think it wouldn’t run at all without going into some sort of derate or limp mode with the emissions missing.

 

I don’t believe they have. If they did, they never said anything to me on it. You would think the coolant temp sensor would make my engine coolant temp gauge read low at the same time. I ordered the barometric sensor in but haven’t picked it up yet.