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.

[catman3126]

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.

Long shot here but is it possible to adapt the 5.9 solenoid? electrical part to the 6.7 injector? or is it different size? I have changed out both but never payed attention to size or compatibility. I know on the LB7 and the LLY IIRC the LLY takes 48 volts and the LB7 takes 96 volts so going to a higher voltage I didn't notice an issue or atleast I don't think I did but could have tuned it with timing tables to not notice an issue. I wouldn't think the internals of the injectors would require the voltage difference would they? just the solenoid itself?

[comnrailpwr]

All very good questions for which I cannot answer. The internals don't care about the solenoid I wouldn't think. I would like to see the injector driver circuit inside the 6.7 cm 2100 ECM. Im wondering if the only difference is the capacitors which may be able to be swapped out if you can get the cases to seal back up.

[catman3126]

very possible. that sure seems like a lot of Amp's but what do I know lol :nixweiss:

[SASDakota]

I thought I had heard on CompD that some were running 6.7 bodies and 5.9 solenoids. There again, it is hearsay as I haven't done it. But maybe gives you a place to search??

[comnrailpwr]

Well still at it. The truck runs and drives. Throttle issue is good now. I have flashed a couple dozen files in with different combinations and for the life of me I cannot get a smooth running truck. It runs like a rapped ape but just runs rough unless at WOT. Pops out the exhaust when free reving slowly. I am flashing some single even files now which seem to do better. When truck is warm it gets better. I think some of my issues are timing related but also injector. The truck rpm fluctuates when coming to a stop sign. The truck idles at 45-60mm3 if my duration is below 775 in the idle areas and starts really slow/soft. It just acts stupid. Am I loosing my mind or is all these issues pretty much 6.7 injector related? Pasting my proven 6.7 maps over with all axis the same does not work at all. If I remember it won't even start because duration is lower than 600 in the idle areas. I am loosing track or what's what as I have flashed this truck so much.

[comnrailpwr]

Well the good news is the single event tunes responded much better with pretty smooth operation. Their is still a little stumbling when coming off the throttle and startup but that seems to be the injector mismatch issue. We won't be able to get a good test in the large tunes until we get on the dyno. Just no traction. But at this point its very drivable. I'm sure it's going to give me fits starting cold in the 7* weather we are having but at least I'm making progress. Ultimately like all others have said, just go 5.9 injectors. I won't do another like this.

[Dmaxink]

Well still at it. The truck runs and drives. Throttle issue is good now. I have flashed a couple dozen files in with different combinations and for the life of me I cannot get a smooth running truck. It runs like a rapped ape but just runs rough unless at WOT. Pops out the exhaust when free reving slowly. I am flashing some single even files now which seem to do better. When truck is warm it gets better. I think some of my issues are timing related but also injector. The truck rpm fluctuates when coming to a stop sign. The truck idles at 45-60mm3 if my duration is below 775 in the idle areas and starts really slow/soft. It just acts stupid. Am I loosing my mind or is all these issues pretty much 6.7 injector related? Pasting my proven 6.7 maps over with all axis the same does not work at all. If I remember it won't even start because duration is lower than 600 in the idle areas. I am loosing track or what's what as I have flashed this truck so much.

What does it do with just a stock tune? Sometimes it's best to cut the losses and just start completely over.

[comnrailpwr]

What does it do with just a stock tune? Sometimes it's best to cut the losses and just start completely over.
I will be back at it tomorrow evening a little. Got a couple more trucks to get out of the way early in the week. I have tried bone stock 6.7 maps. It still revs like crap with the missing and white raw fuel smoke. I started the truck today here, 10 degrees out. It misses and sputters bad for a few seconds then it's back to the hazy idle. It runs phenomenal on single event tunes when it's warmed up. So in short cold weather operation still sucks. When the truck is warm it starts with zero issues, nice and smooth. I didn't have my v2 with me tonight but tomorrow I'm going to try and get some more data. I also did figure out their is some sort of traction control in play. When the tires break lose while driving the ECM starts defueling. When in 4wd it doesn't defuel at all weather you are launching for just giving it all it has.

[DURAtotheMAX]

Sounds just like an LB7 FICM running LLY injectors. The solenoid coils are rated for different voltages, and thus draw different amounts of current (remember, ohm's law)...which makes for a crappy running and all but impossible to tune 100% correctly engine.

Its a pain. It can work, but it will never be perfect...and you'll waste a TON of time tuning it.

[comnrailpwr]

Yeah I agree. I'm gonna spend one more day with it and get rid of a couple minor issues, then turn it over to the customer. Already told him he's going to want to get into a set of 5.9 injectors and he agrees. He said he figured so and knew that may be the case going into this conversion.

[arinkuddy]

Just a thought but did you try increasing the PW a substantial amount, across the whole PW table. If the injectors are under volted they might just need more time to open.

[tylerltr450]

Just a thought but did you try increasing the PW a substantial amount, across the whole PW table. If the injectors are under volted they might just need more time to open.

Good idea but I wonder if that would be a bad idea because if they so happen get more voltage it might cause to much PW??

Just a thought.

[comnrailpwr]

Just a thought but did you try increasing the PW a substantial amount, across the whole PW table. If the injectors are under volted they might just need more time to open.
Yes I have tried that. That is the only way I can get my mm3 quantity at idle in check. but it seems is still wants to idle at a high mm3 when its really cold out and the engine is cold. The consensus is the conversion can be done but it is far from perfect. You can tune all you want but in reality tuning doesn't fix hard part mismatch. My customer is going to be going to 5.9 injectors at some point but for now the truck is extremely drivable and and will lay down more power than it did with the 6.7 ECM I feel. The truck also launches a lot better because it could care less about Engine load.