CUMMINS SWAP 2250 to 2350.

[Rawze]

(01-02-2021 )ESDrepair Wrote:  the only reason we used the 2350 ecm with the 2350 motor we were told that it don't work with the injectors but what you are saying makes a lot of sense pissed i wasted so much time with that old harness but it is what it is.

i don't have cal term do you have a file you can send me

yeah truck is deleted and motor is.

Yeah, you wasted a lot of time and effort.

It would have run by just slapping the 2250 ecm and harness on it and not given any grief or faults, but it would not have been quite right. Efficiency would have suffered by quite a bit unless a program is made. What is actually different between the 2 model engines is easily compensated for in the ecm though. I have written my share of custom programs from scratch in them for going both ways (2250 ecm and harness onto a 2350 hardware block .. and 2350 ecm and harness onto a 2250 hardware block) quite a few times in the past for people, as there is no official solution to this.

As far as using/programming a 2250 ecm and harness to run a 2350 engine ...

* The injector hardware itself is compatible (the electrical coils, etc), that is not an issue... however the trim codes themselves are calculated differently on 2350's inside the ecm. It is an easy enough matter to fix though, it is simply a matter of putting the trim calc settings into the older 2250 ecm along with some minor tweaks. There are actually fewer settings in the 2250 ecm than a 2350 so it is actually easier to make the changes inside the 2250 to run a 2350 engine than it is to go the other way (2350 ecm on a 2250 engine), but both are possible and have been done.

* The compression ratio and injector spray angles are different between the 2 engines. This means some minor adjustments to the injection timing, fuel-air-mix, boost requirements, mass air flow requests, and a few other things related to the combustion stroke to compensate the diffreences. The engine will run without any of these changes but it will have a shortened life and efficiency will suffer to some minor to medium extent. It is not a difficult thing to fix though, but it needs to be done to ensure engine longevity and proer engine efficiency.

* Making any changes to what hardware/sensor differences there are between the 2 engines. most of the time the shop will take the wiring harness and the ecm off,... and then any sensors that are not on the other engine + remove any the other engine may come with that are not needed/extra .. but the program can be fixed to compensate for any differences too. Things like if there is a crank case breather heater option or not, intake throttle body installed or not, etc.


It has been done many times on here, I have had to do this with several people. This is because There are likely very few people who would understand the issue well enough in detail or the programming to get it right. This is especially in regards to editing the fuelling controller so that it properly calcs the different type of injector trim codes. I have gotten referrals from several of the OEM shops that sometimes use a 2350 engine/block to replace a 2250 in a pinch. They usually just slaop the older ecm and harness on there and call it a day... In their ignorance to it all, to them, the engine runs fairly ok outside of lower fuel mileage, power/performance differences, etc. and the truck owner complains about it in many of those cases. The issue is that there is no program they can slap in there from quickserv, so they refer people to me (or this forum) fairly often for custom programming of the old ecm.

As far as getting the software to pull the files out of it yourself, that stuff is on the internet for free if someone looks in the right places. Those ecm-butchering auto-tuning sites like to make it seem impossible to get and try to hide everything so they can charge moneys for it, but it can be had without having to resort to that. Maybe you get lucky and someone point you in the right direction.,.. however I do not allow software trading/links publicly on this forum. This is a help forum, not a software trading site.

I PM'd you my number. Your welcome to give me a ring.