Limp mode? with new dsp5 and tunes

[smitty91]

Here's about a 10 minute log of the truck going into "weird mode." for about the first 2 minutes the truck is normal and then it goes into this mode all of a sudden like someone flipped a switch. Thanks

[8100 Power]

Have you tried the Stock Tune yet?

If it doesn't do it with the stock tune, then it's your tuning.

[smitty91]

yea I have, it doesn't do it on the stock tune. Thats what i'm thinking. Hopefully Nick can find a problem.

[vortecfcar]

I've been out of town the past 2 days guys.. sorry for the delay. I'm looking into the problem now. The log shows rail pressure is fine.

The truck hitting a fuel (mm3) limit that doesn't seem to want to reveal itself. All torque limiters are maxxed out.

It's odd that the MAF is reading nearly zero. This appears to be a mixture limit issue. I have not rescaled the MAF or played with any mixture tables. This is the second truck I've seen this on, both LBZ. I rebuilt and rescripted the tune on the other truck and that cleared it up. I'll try that on this one. Should fix things, cross fingers.

It's like something is corrupt in the file and forces the MAF input to be interpreted as zero or near zero, thus limiting fuel....?

Nick

[giesbrecht]

I've been out of town the past 2 days guys.. sorry for the delay. I'm looking into the problem now. The log shows rail pressure is fine.

The truck hitting a fuel (mm3) limit that doesn't seem to want to reveal itself. All torque limiters are maxxed out.

It's odd that the MAF is reading nearly zero. This appears to be a mixture limit issue. I have not rescaled the MAF or played with any mixture tables. This is the second truck I've seen this on, both LBZ. I rebuilt and rescripted the tune on the other truck and that cleared it up. I'll try that on this one. Should fix things, cross fingers.

It's like something is corrupt in the file and forces the MAF input to be interpreted as zero or near zero, thus limiting fuel....?

Nick

I'd like to know if you find anything on this, Nick, I'm beating my head against the wall on an LBZ doing the same thing. It's an early 06 if that makes any difference. I have tried changing the OS with no luck.

[vortecfcar]

Hopefully Walker chimes in and lets me know if the rebuilt tune fixed the issue. Strange indeed.

I have another customer who thinks he may be experiencing something similar, albeit more intermittent. I've asked him to log MAF rate to see if we can draw some parallels.

O.S. on Walkers is: 52606128
O.S on the previous truck was: 52616698
O.S on the newest suspect: 52616698

I have yet to see it on the latest O.S. - Might be the one to try to update to Harley...

[8100 Power]

I went through the same same with a LMM.

It also hit a fuel limiter within the tune. I'm not sure what the problem was, after a re did the DPF delete options it finally worked correctly.

[vortecfcar]

I went through the same same with a LMM.

It also hit a fuel limiter within the tune. I'm not sure what the problem was, after a re did the DPF delete options it finally worked correctly.

8100,

Doesn't sound the same. Unless the MAF readout is showing zero or near zero while logging, it's not the same deal. DPF delete trucks will often run into limp mode problems and a visible 'reduced engine power' notification (easy fix like you said). This truck is not exhibiting those symptoms and not subject to that fix :( .

Nick

[giesbrecht]

Hopefully Walker chimes in and lets me know if the rebuilt tune fixed the issue. Strange indeed.

I have another customer who thinks he may be experiencing something similar, albeit more intermittent. I've asked him to log MAF rate to see if we can draw some parallels.

O.S. on Walkers is: 52606128
O.S on the previous truck was: 52616698
O.S on the newest suspect: 52616698

I have yet to see it on the latest O.S. - Might be the one to try to update to Harley...

O.S. giving trouble: 12616698
O.S. I'm trying now: 12606128
Still limiting but I'm still working with it.