Yeah, well my car is running super rich and we tried to lean it out some, turned the FPR down some, no matter what its idling like a 10 afr and cruising around 10afr. under boost its 11.5 which I am happy with. but its just not responding to tuning changes. Any ideas anyone?

 

what are your injector settings and lag in setting 5 on fc-edit , if you have a datalogit if not what are your settings in the commander?

 

I dont know off the top of my head. Ill check it out. I was staring at your profile pic for like 10 min btw lol..

 

With street gas cars: stock 850s as primaries, and larger others; have always been known to have idle tuning problems due to PFC idiosyncrasies.
Thus running negative lag has become common to reduce idle fuel flow.

Many say the high impedance ID 725s idle perfectly with 0 lag.

550/1000 = 55%, Q = 1000, lag is what ever it takes.

 

I seem to get that response a lot on here

 

Yes it takes my imagination to places I would like to go

 

like my lag is set at .40

and now its acting crazy. I let off of the gas to idle and it bounces from 2-2.5k with the afrs swinging to 12-18. until it drops back to regular idle. Wierdddddddddddddddddddddddddddddd.

 

Bouncing idle is due to the combination of: TB air flow, fuel, timing, ISC setup, injectors setup, air pump setup, and O2 FB setup.
Until you post your map with all engine mods, we are all in the dark.

 

Do the numbers on a 96 lb/hr (1000 cc/sec). There is no way the injector pintle can cycle (for the Bosch style) less than 1 ms to achieve a realistic AFR for a stock engine idle at 700 rpm. The PFC also cannot drive to such a low duty cycle unless someone here knows some black magic I don't.

You need to get your primaries back to less than 850 cc/sec and work towards larger secondaries or even supplementary injectors.

 

they are precision 1000cc top feeds. duty cycle is at 55% currently.

 

Precision are Bosch style and these are low impedance so you must either have the PFC drivers supplemented with resistors or a driver box. If you have the resistors the peak and hold demand of the injector on the PFC for good pintle initial movement is challenging due to the initial movement inrush current. What this means is the opening and closing of the injector will be lazy and difficult to manage at low cycle duties.

Your 55% duty cycle cannot be for idle - the engine would not run. For such a large injector to obtain a decent AFR at normal idle the duty would be less than 2ms. Now add to that unstable pintle movement and it gets worse. Below is from a log using 550 high impedance primaries.

Rpm InjDuty InjFrPr InjFrSc Boost WBO2 PIM V TPS V
963 5.1 3.228 0 -367 12.61 1.768 0.419
960 5.1 3.236 0 -365 12.62 1.769 0.419
949 5.1 3.252 0 -364 12.639 1.776 0.419
944 5 3.252 0 -362 12.698 1.775 0.419
960 5.1 3.22 0 -362 12.727 1.777 0.419
947 5.1 3.244 0 -363 12.727 1.773 0.419