5.9 ECM in 6.7 Tuning Issues.

[comnrailpwr]

I have a customer who converted ecm in his truck for competition reasons. they did the harness themselves. for the life of me I cannot get the truck to run right. I am aware of all the differences with the hard start, tps issues, injector amperage differences ect.. The truck has no throttle response but i think that is due to the way the truck is running or the 6.7 tps. this is my first time doing this swap and i just want to know if i am missing something. this is the 3rd ecm on this truck. 1st ecm had an injector driver issue droping out bank 1. second ecm wouldnt communicate. this ecm acts like the first but hasent thrown any codes relating to injectors. turck idles at correct rpm. smokes a ton of raw fuel and sounds to be down a few cylinders with a terrable miss. the truck is far from stock and has 175% over noszzles. i have rueled out any issues besides my tuning and his harness. i cannot figure out why it wants to idle at such high mm3, which drives pulse up which gives me all my white smoke. please if you have expierence with tuning a swap as such let me know if i am lost on this. attached is a tune file and a log. operating systems i have tried are 409, 602, 202. i have tried with both checksums disabled and enabled. pm me if needed. thanks guys

[Moparmatty]

What happens if you flash a 100% bone stock file in it?

[comnrailpwr]

I have flashed a file with stock 6.7 maps with same results. Never tried to flash just a bone stock 5.9 file although it should idle fine with it. I'll try it this evening. I just can't figure out why it wants to command 50+ mm3 at idle no matter what I do. I'll see what mm3 its doing this evening when I start it up. Thanks for the response.

[tylerltr450]

If you flash a 5.9 tune it will probably run like garbage. Did you change all parameters to replicate a 6.7? I am interested in this because I will be doing this on a persons truck for pulling also.

[anarchydiesel]

If the truck still has 6.7 injectors you are fighting a losing battle. They can be made to run, but not well. sounds like there may also be a harness issue, but definitely going to need 5.9 injectors especially if you are trying to make big power and turn high rpms.

[comnrailpwr]

If you flash a 5.9 tune it will probably run like garbage. Did you change all parameters to replicate a 6.7? I am interested in this because I will be doing this on a persons truck for pulling also.

It would not run correct with the spray angle and piston design with 5.9 parameters but it should idle fine, just be smokey during driving conditions. Yes I rescaled everything for 6.7.

If the truck still has 6.7 injectors you are fighting a losing battle. They can be made to run, but not well. sounds like there may also be a harness issue, but definitely going to need 5.9 injectors especially if you are trying to make big power and turn high rpms.

Yes still 6.7 stix. He already put 5.9 injectors in it once with the first ECM. He switched them back when we realized we had an ECM issue. I knew they were troublesome but this truck is not drivable at all. From what I gathered they just caused some stumbling startup issues. Did you have some that smoked and missed bad? I can try and get a video tonight.

[catman3126]

Sounds similar to the tuning issues I ran into doing a LLY in a LB7 truck with the LB7 ECM/FICM. wouldn't hardly idle let alone drive when I started. 2.5 days a flashing and driving and I finally got it. but man what a headache.

[comnrailpwr]

Yes it is. Got it all sorted out with some help from s member on competition diesel. My issues were OS related I believe.

[catman3126]

Good deal. good to know this could be done.

[comnrailpwr]

It can certainly be done. However there's a little bit of known issues that go along with it. The CMB ECM does not like to fire the 6.7 injectors probably. The 6.7 injectors require significant higher amperage to open then the 5.9. 26.7 injectors require 24 amps to open and 18 amps to hold them. The 5.9 injectors require only 18 amps to do both. I still have a lot of tuning to do but there will always be a little bit of a stumble at startup and throughout the RPMs. They're just not smooth. On competition Truck this is usually not a concern. If I was doing this to a daily driver I would use 5.9 injectors and a 5.9 TPS.