Fuel injection for DPF

[jaird]

Did Ram change the fuel injection for DPF on newer vehicles? The system of injecting fuel into the engine instead of the exhaust line seemed to be troublesome.

Thanks in advance for replies.

 

[EDankievitch]

For the 2013 model year Ram/ Cummins went with the SRC emmissions system (DEF) to deal with the Nox emmissions. This allows the engine to be tuned to run much clean burning as cylinder is allowed to run hotter. Much less soot is made so the Re-Gen cycle is not needed as often. Also the DPF was re- located closer to the engine so it gets hit with much hotter exhaust gasses this allows it to light off passively as opposed to active as with the per 2013 model year trucks. The computer will put the engine into an active clean out as needed when the truck's duty cycle does not allow it to self clean. This is much less often than the older trucks. As a result the newer trucks give much better MPG's. In my case my 2012 would deliver 12.5-13.5 around town (550 miles a week at aprox 45 mph) and 18.4-18.75 on the highway. My 2013 delivers 16.5-17.75 around town and 21.5-22.75 on highway. Also my 2012 would demand it's oil to be changed every 1800-2100 miles the 2013 is showing 15000-16500 miles for oil change intervals and the oil is much cleaner. The consumption of the DEF fluid seem to be right around 1 gal for every 850-1000 miles. So the extra cost of having to buy DEF is not an issue.

 

[jaird]

Thanks. That looks like a great improvement.

 

[rscurtis]

I think the Duramax has a ninth injector for regeneration. Fuel injected into the exhaust was the death of the 6.4 Ford and has been problematic on the 450/550 platform with the 6.7 Scorpion engine.

 

[jaird]

What would cause fuel injected into the exhaust to cause trouble in the 6.4 Ford? I can understand injecting into the engine causing trouble.

 

[rscurtis]

I should have clarified my statement. Fuel in the 6.4 was injected into the two rear cylinders, where it would burn in the exhaust and overheat the two turbo's, leading to failure. Search for videos by the Powerstroke Doctor in Atlanta, you'll be amused for hours.

 

[jus2shy]

I've perceived about 4 active regenerations on my truck so far in 6,000 miles. I can smell it when it does go into regen and it stinks when you're at a stop light. It still injects fuel during the exhaust stroke to pass fuel to the DPF. Thankfully if you get a good amount of highway driving in, you should almost never have an active regeneration take place. I really like the fact that they make the passive regeneration so much more practical. Even the Ford guys with 6.7 scorpion motors note that they regen about every 200 to 300 miles. I'm happy with noticing a regen every 1000 miles or so with my duty cycle. If you do more city driving or idling due to winter though, expect more active regeneration events. And as a quick note, I'm 60/40 City/highway in my duty cycle. So you don't have to have that much highway miles on your commute.

 

[slingshot383]

I've heard wrapping the exhaust from the turbo to the DPF chamber will help.