Is there a way for me to tell if my fuel system is suppling enough fuel to my motor when I'm at the upper end of the boost & RPM's. I have a 04 C5 coupe with procharger SC, AR long tubes headers, corsa exhaust, 10% overdrive IW Harmomnic Balancer, Alky methanol injection pump with boost-a-pump & racetronix harness. The reason I mentioned the racetronixs harness is it supposed to supply up to 22.?v to the fuel pump when it's needed. My tunner did tell me that I was right on the edge of the fuel system not supplying enough fuel. He said he basically gave it a conservative tune so it wouldn't run out of fuel. I have a wideband AFR gauge, but to be honest I'm not sure how to inturpet the readings. The user manual that came with it said it should read about 14.7 at idle and it does and 10 is rich, while 20 is lean. What I don't get is that seems to be the gauges maxium range from 10 to 20. If I go out and have a lot of fun in it when I get home before I turn the ignition off I check to see what the maixum ranges are and the AFR gauge always says 10 & 20. Also I usely check them when I start the car to make sure that it is reseting the values for a new reading. I did notice that it seems to max the lean side out after a good boost run when I let up off the gas pedal and I'm coasting or slowing down. Can somebody explain theses readings and is there a way to determine if my fuel system is supplying enough fuel. Thaks for any help.

 

What the AF #'s when your beating on it. Richer is ALWAYS better when you force more air in.

 

A wideband may not react fast enough, or at the other end, be changing so rapidly you cant read it at speed. Do you have a fuel PSI gauge? If demand excedes supply, it will drop.