Ok, the car is running good but not great. My main problem is I am averaging 7mpg. This is my primary driver and it's killing me. Plugs are good, clean air filters, new fuel filter, walbro 255, stock injectors, the car is tuned in open loop so the o2's shouldn't have any kind of difference. What else can I look for? The a/f is right around 11.6-12.4 and it makes no difference wether I am on it the whole time or keeping it under 2500. Where should start looking to get this thing running better? Mods are 1995 Z28 M6. Stock other 383, decked LT4 heads/ intake, CC306, MAC mids, Borla catback, Delteq, SLP CAI, Vortec elbow, BBK 58s, Eibach Pro Kit, Spohn torque arm... TUNED BY HPA

 

probly your tune

 

Wouldn't the a/f reflect that though?

 

it looks like it is......looks rich to me but i don't know much about it........I thought most run leaner than that on a street car

 

So should I be trying for something closer to 13.5-14?

 

Its running way too rich. At low RPM/part throttle/cruise you want it in the range of 15.2-14.7:1. You only want something closer to 13.0:1 at WOT. 11.6:1 is pig rich.