MazdaMike

turbo camaro friend all custom stuff he made is tryin to tune his crap but when he lets off from WOT it goes very lean (18-20:1) and his injector flow goes to 0. the car also has a tendency to stall after giving it gas. he has only completed all the piping of the turbo system last monday so he hasnt had much time other than a few goes up and down his block.



my question



is that normal to lean out when off the gas? is that ok. cause my 7 was going to 0 injector duty when off the gas and it seemed fine, then again it was pinging at midrange rpm and the tuning was for ****



what might cause the stalling the idles just die. it sounds like the engine is choking out. could the bov be venting too much or not enough to mess with the mass air. the sensor is mounted in the throttle body though so i dont think its like a VW where you have to have the vented air return to the system



anyway any tips or things to look for and i would appreciate it.



-mike

RETed

Yes, it's call the decel fuel-cut.

It saves gas and allows the engine to decel faster.



If it's stalling from lifting off, the decel fuel-cut RPM re-engage point is set too low or the high vacuum maps at the re-engage points are not tuned correctly.







-Ted

GreyGT-C

what ECU is he using? Some ECUs can toggle the decel fuel cut on or off depending on what you are doing with it. Makes for hellacious fireballs on rotaries....



Dependin on which ECU he is using, we might be able to tell you how to raise the re-engage rpm on it also.

mazdadrifter

since i premix and after doing pulls on the interstate, i don't like the idea of the motor coming down from redline w/o any lubricant, i actually turned the de-cel fuel cut off, and just leaned out my very strong vaccum settings, (~27-30in/vac) which is essentially doing the same thing, but not cutting fuel completely, just adding it enough to lubricate some, so it helps me sleep at night.