LMM and LBZ DSP5 Desired boost tables not looking up correctly

[vortecfcar]

On build 7.5.6 (133) I've logged instances of both LMM's and LBZ's failing to engage the turbine brake which I've written into the tune using the desired boost table (amongst others). The scripts have worked in the past, but recently stopped. Further investigation points to no significant change in 'desired boost' PID when I switch the DSP. It should jump up 200kpa like it has in the past.

If you need any more information, let me know and I'll be happy to provide it. Tunes and logs can be sent via email if necessary.

Hopefully its something simple, thanks guys :)

Nick

[bballer182]

Nick, as im sure you are aware tables B2231 and B2232 as set from the factory to ignore the boost tables when there is no commanded fuel. I personally have had no problem at all with writing in a turbine brake in either the base tunes or DSP 1-4.

BTW i have never had to alter the boost tables to tune for turbine brake, just the vane table.

If you would like any help tracking down the problem i'd be more than willing to help you.

[vortecfcar]

I have the DSP2 vane tables set to 100%, the boost tables set to 30. Max in the base is set to 100, min to 0 in the appropriate rows. I get no change in the desired boost or vane position. I know it's worked fine in the past, now all the sudden I get no change. You may have to download the latest release and convert a DSP5 from a stock .cal.

What's your O.S. # I'll send you one to try.

Nick

ps- Looks like I'm not the only one (click) (http://forum.efilive.com/showthread.php?11753-LMM-OS-12628594-boost-tables/page3)

[bballer182]

So aside from the problematic 8594 OS you are seeing this in the LBZ OS's as well?

I'm running 52616698.

[vortecfcar]

See attached. The Boost should jump 3 lbs when in the DSP#2 position and the turbine brake should work. Hopefully you have better luck than I :)
Nick

[bballer182]

I guess I'm just lucky.:)

Anyways, Anything else i can help you with?


9261

[vortecfcar]

Or I'm just a moron. ;)

Interesting... can I ask you to try a couple of other O.S.'s? The 2 recent LBZ trucks where I had this issue had the older and newer O.S.

Hopefully these give the same logs so I can apologize to Ross and Paul like usual and move on to chasing my tail. :)

Thanks Baller,

Nick

[bballer182]

Something i noticed just now is that you are not disabling the EGR, which, could be the problem because in the DSP folders the only vane and boost tables are for EGR OFF. I'm surprised that it worked for me last night. I'm on my way out to go test the 2 other OS's right now. will edit with details.


All OS's appear to be working as intended. I did shut off the EGR before trying these last two. So that may or may not be your problem

[vortecfcar]

Bballer,

Thanks for your testing, but I need to verify with EGR on as well. That's why I left EGR function untouched. This has to work on Bosch trucks without the blocker installed. I've had drivability problems on Bosch trucks with the EGR function disabled and no plate installed.

Nick

[JoshH]

Bballer,

Thanks for your testing, but I need to verify with EGR on as well. That's why I left EGR function untouched. This has to work on Bosch trucks without the blocker installed. I've had drivability problems on Bosch trucks with the EGR function disabled and no plate installed.

Nick

What kind of problems? I've never noticed any problems.

[vortecfcar]

Surging, loss of throttle response - smoking.

[bballer182]

Bballer,

Thanks for your testing, but I need to verify with EGR on as well. That's why I left EGR function untouched. This has to work on Bosch trucks without the blocker installed. I've had drivability problems on Bosch trucks with the EGR function disabled and no plate installed.

Nick


What kind of problems? I've never noticed any problems.


Surging, loss of throttle response - smoking.


Up until recently i've had mine shut off but not blocked for a couple of years and have had none of those issues.

If i were to guess i would say those symptoms are from the ECM switching back and forth between EGR ON and OFF tables in the DSP folders.

[vortecfcar]

I see these symptoms routinely on trucks with single tunes and trucks with DSP5 tunes. I get about 5 calls a week from customers who attempt to shut the EGR off in the code and get the symptoms I describe (smoking, surging, dead pedal). I tell them to put blocker plates in or put the EGR operation back to stock. This fixes the problem every time.

I've tried disabling the EGR in the software a number of different ways without success. If you want to share your EGR off parameters I'll try them on a few trucks and see if I get consistent performance.

Nick

[bballer182]

This is how i've always done it.

[vortecfcar]

Your script sets all EGR function to stock. :)

[bballer182]

HAHA, whoops. got the scripting backwards.

[rcr1978]

Here is mine, I also zero al 3 flow tables

[JoshH]

I see these symptoms routinely on trucks with single tunes and trucks with DSP5 tunes. I get about 5 calls a week from customers who attempt to shut the EGR off in the code and get the symptoms I describe (smoking, surging, dead pedal). I tell them to put blocker plates in or put the EGR operation back to stock. This fixes the problem every time.

I've tried disabling the EGR in the software a number of different ways without success. If you want to share your EGR off parameters I'll try them on a few trucks and see if I get consistent performance.

Nick

I don't think a big time pro tuner like yourself needs any help from me, but I have NEVER had any kind of those problems from disabling the EGR without a blocker plate. I have recently put a stock motor back in my truck that is running without a blocker plate and the EGR shut off. I've also had a disabled EGR tune in my dad's LMM for about 60k miles with none of those issues. I've also tuned a few trucks locally with the EGR shut off and no blocker plate. No problems here.

[Dozerboy]

I can't say that I did neither, but that was a while ago. I don't think I changed much other then the speedo and EGR until after I had the plate and transgo though.

[killerbee]

Also, I do seem to recall that messing with the EGR flow tables led to the issues you report. EGR is best disabled without touching them. I don't know why, however.

These ECM's are like drug interactions sometimes.

[rcr1978]

Also, I do seem to recall that messing with the EGR flow tables led to the issues you report. EGR is best disabled without touching them. I don't know why, however.

These ECM's are like drug interactions sometimes.

Weird, I've done 7 different trucks exactly the same way with no issue's at all must be that one bastered child every so often :fluffy: Or a certain problem OS

[killerbee]

I think it was LMM that caused problems for me when I zeroed the flow tables. Again, going from an abused memory, iirc it caused the EGR to open and really wreak havoc, the kinds of symptoms Nick's customers report, aka driveability issues.

[Pela]

I have run into these EGR problems as well but what I believe occurs is the EGR valve begins to leak due to the buildup that occurs from it not functioning as designed. I have tuned trucks with very low mileage ( less than 5000) and not had a problem until sometime later. Other trucks with more mileage have the leaking EGR right off the bat. Personally I block them if I want to disable the EGR Function. There are too many other tables like EGR operation and diagnostics that control it's function to keep it nailed shut.