Blitz Fuel/Timing Issue

[CrankyOldMan]

That makes sense then--one function of the blitz switch module is to force the ecu into open loop, which makes the injectors run rich. I'm not sure how you could make the ems do the same, since I don't know how you trigger the clutch on the blitz...

[CTScott]

Originally Posted by CrankyOldMan

That makes sense then--one function of the blitz switch module is to force the ecu into open loop, which makes the injectors run rich. I'm not sure how you could make the ems do the same, since I don't know how you trigger the clutch on the blitz...

The blitz fuel controller is just a very primitive fuel adjusting device. It simply looks at the MAF signal for the amount of air flowing in and holds the injectors open longer in proportion (and with targeting a lower AFR when the clutch is engaged). It by no means has control of open or closed loop. That is a very controlled process that the ECM does itself and to override it you have to basically put the system in a fault condition (which the Blitz does not do).

This is also why over time you start running leaner with just the Blitz fuel controller. In its closed loop mode the ECM sees that the AFR is lower than it wants it to be and it constantly fights the Blitz controller with trying to trim off the extra fuel. Resetting the short term fuel trims regularly (by pulling the battery cable for a couple of minutes) will help a bit and doing a full reset of the long term trims (by doing a full reset of the ECM with TechStream) will help even more.