speed limiter

[THEFERMANATOR]

I did a tune for somebody in an 05 LLY, and he wanted the speed limiter raised to 120. I raised it just like I have in any other tune, but instead of raising it, it removed it altogether. Has anybody else run into problems with the speed limiting tables in an LLY not working? I know I had B0747 set to be 0 fuel at 120, as well as all 3 limiters set to 120, BUT his daughter jumped in the truck and took off and got a driving achievement award of 128 in a 55. He brought it back and had me drop it back to stock until his daughter moves out to keep from getting anymore awards of that size, but want to make sure for future tuning if this is an issue I need to tell customers about or not. And I did verify the speed with a GPS VS the speed PID in a datalog, and at 70 they were spot on to each other, and they said that the speedo said 130 when she got her award, so the only limiter it had working was the rev limiter.

[Mitco39]

I might suggest changing out the OS to 1 of the other 2 main ones and giving it a shot?

[THEFERMANATOR]

I might try that later on. I know it was just flashed by GM last October when he had it in for head gaskets. The shop gladly took out his finger stick, blocker plate, flashed in a stock tune, left him with a check engine light, and then hit him with an estimate for $1300 to put an EGR valve in it after the had already hit him for $5K for the head gaskets. And oh yeah, they didn't bother to keep any of the injector lines clean or injectors, so when they fired it up it plugged up 6 of them so he had to have 8 new injectors and lines put on it at my buddys shop. So I put a basic tune in it to shut off his light and give it a little kick, but this speed limiter has me stumped why it won't respond. The catch is I sure aint gonna go out and drive it that quick to verify it is fixed each time I make a tune change. I have no desire to drive a lifted 3500 dually on 34's at 120(this guy is a bit nuts, but his moneys good).

[Mitco39]

Then why not just lower the speed limit to 45mph and test it that way? If it works down low it should work at all speeds. I again would suggest just doing a full flash and trying a few different OS's to see if one works. Its solved my issues in the past.

Goodluck

Mitch

[THEFERMANATOR]

It worked fine at 98 where it was set at stock, that's what has me scratching my head. The only thing I changed(on that version of the tune) was I raised it to 120 for him, and it goes to 128 at the rev limiter. It's not a huge deal, just wondering if this is a known issue or just an LLY quirk.

[killerbee]

If I was wagering, I would bet the logged VSS at defuel probably coincides with your speed limit. It wasn't clear to me if you had logged it at the speed limit. I have noticed that VSS does not necessarily coincide with actual speed under load. For example, I can create a 2 or 3 mph VSS while stationary in our LLY.

[THEFERMANATOR]

It was just wierd that set at 98 where factory was, it worked fine, raise it up and it drops the limiter off completely. I've come to the conclusion if it doesn't start with an LB, I don't like doing tuning for them. SO far I haven't had any of these wierd quirks with my LB7, and all of the LBZ's to date have gone well except for the P0102 error code that myself and several others have gotten.