What have the issues been with LMM'S?

[LBZoom]

Hey guys,
Just wondering what everyone has run into so far with tuning the LMM's and how you overcame it? I know there are a lot of threads in here about guys and their LMM's but rather than look for them all I'd like to make a "summary" thread. Thanks for any input guys! :cheers:

[GMPX]

Good idea, would be a nice reference for everybody.

[camcojb]

I can give a few for the twin turbo or aftermarket turbo guys who run high boost. Most of these are just high boost issues, but I think the pilot timing one would affect everyone.

1. Turning pilot off. You can shut the tables off, but you'll still have a small pilot. You have to go into the fuel pressure table and change the max pulses allowed to 1, which creates issue #2.

2. Limited timing. Once you get the pilot off there is some other timing limiter table that has not been found. Mine maxes at 28.5 degrees, regardless of what you set the tables to.

3. Limp mystery. With the twins I would get a dead pedal limp, no codes or lights. Wasn't even after going wot, usually happened on a long cruise down the freeway. Come off the freeway, stop for a red light, and when it turns green you push the pedal to find that you're in limp mode. The OS that did this for me was #7103. I did a full flash to a later LMM OS and that disappeared.

4. New one I found tuning a friends truck that tows heavy (25K to 30K+ all the time). If I shut off his egr in the tune it would get an intermittant backfire "sneeze" sound when he was under the most load, like accelerating from a start of climbing a big hill. Turned the egr back on, immediately gone. No idea what that was, as I've done several tow tunes on the same year trucks without issue. None of them tow that heavy though.............

5. There also appears to be some sort of torque reduction built into the LMM OS. I have tried three different LMM OS's, with several known good tuner tunes and my own tunes, and there is still defuel allowed. Now it's fine at normal throttles up to 50% TP or so. Then it starts, and at 50-65% TP it gets a fair amount of defuel on shifts, even if you have TR shut off in the trans. At WOT you can't feel it, so I just avoid that particular throttle position. The tune can make it better or worse depending, but I have yet to find a tune that is smooth in that area with the higher boost twins.
Jody

[duramaximizer]

Tow haul for me by the seat of the pants seems to defuel less also.

My .02 trans tuning cough?

[duramaximizer]

Any one having problems with the LMM's and timing over 27*'s on the 12617103 OS. I haven't switched over to the 8594OS yet. I have tables over 27*s but my scans are not showing the timing I have desired. I am just wondering if anyone else have found a problem with this.