PDA

View Full Version : LB7 Speed Limiter/ High speed defuel???



larski156
April 7th, 2016, 02:21 AM
Been working on my first LB7 tune for a buddy, got a pretty good DSP4 made for his big power tune. Been chasing a weird de-fuel problem.
Its not consistent, but usually around 90MPH, the pulse width will drop like a rock for no apparent reason. But the thing will continue to speed up, and eventually after some time or some throttle fiddling it will take back off clear to 120MPH with full PW.
Other times its wont de-fuel at all.

I have been through all the limiting tables I can think of, speed, trq.... ect.
Nothing in the DTC looks like it would be messing with the engine.

Anybody had this issue and know what the culprit was?

I have the tune and data log.
Frame ~1231 is a good example of the PW falling off.

larski156
April 28th, 2016, 10:51 AM
Been working on my first LB7 tune for a buddy, got a pretty good DSP4 made for his big power tune. Been chasing a weird de-fuel problem.
Its not consistent, but usually around 90MPH, the pulse width will drop like a rock for no apparent reason. But the thing will continue to speed up, and eventually after some time or some throttle fiddling it will take back off clear to 120MPH with full PW.
Other times its wont de-fuel at all.

I have been through all the limiting tables I can think of, speed, trq.... ect.
Nothing in the DTC looks like it would be messing with the engine.

Anybody had this issue and know what the culprit was?

I have the tune and data log.
Frame ~1231 is a good example of the PW falling off.

bump

The Neens
April 28th, 2016, 11:11 AM
I would take a look at B0732-B0736