Help! Turbo Afr Consistancy Problem???

[nitrorocket]

Ok, I am having a problem with inconsistant actual AFR'S throught the entire map. In open loop they vary about 1-2 points on most cells, but some cells are always almost dead on???

In closed loop, the AFR varys up to 5 AFR points!!!, but the overall average is more consistant.

I have not been able to track this down to anything except maybe turbine speed?? Through out the range the turbine could be spinning at slightly different speeds making the AFR vary. I think it varys wider in closed loop due to the compputer trying to maybe overcompensate.

Also, in closed loop the pulse width will go down to arounbg 1.28 and run lean enough, but in open loop it normally stays around 1.45?? Odd hey??

Any one with deep thoughts?? (Not by Jack Handy)

[TAQuickness]

Set up a scan map for {B3701} using your WB BEN as the data parameter. After filtering transients, you BEN's from column to column should be the same.

[nitrorocket]

I have and they are way off. EERY time I log some cells vary +-5% or more on the bens??? If I hold fairly steady speeds it is pretty consistant, like freeway driving where I am only using a small area of the map. They are pretty much dead on. During varied throttle or city driving, they afr and bens are widely varied. Its gotta be the turbo variables??? Who else runs turbo? What does yours do??

[TAQuickness]

Jfpilla had, or participated at least, in a good thread on how to adjust B3701. I would imagine you will need to tweak this table to see any kind of consistancy with those injectors

[Ira]

Before I begin I should just say there's every possibility that what I'm about to say is nonsense, but it might be a possibility.

I assume by going to 96lb injectors you've also gone to low impedence injectors with some sort of interface device. If you have a way to monitor the 12V supply to the injectors or the interface device as you drive around you might get an idea if that might be the problem. Two resistors, a 5K and a 10K in series with the 5K solidly connected to the ground closest to what the injector drivers use for ground, the 10K connected to the 12V to the injectors, preferably at the end of the wire and the middle connected to one of the analog inputs on your EFI Live. That will let you log voltage and see if it's moving at a similar rate as your AFR problem. If so, you might want to beef up the 12V and ground supplies to those points and get that voltage to stabilize.


Also, if the interface device allow adjusting the open and hold setting for the injectors you might try slightly increasing the open time or current on the off chance it's set a little on the low side.

Ira