I have a 94 camaro z28 6 speed, ported heads stock valves, port matched intake, C.C 1.6 R.R, pacesetter longtubes, flowmaster exhaust, SLP cold air kit, pcmforless tune, pulleys. It has the stock injectors and fuel pump and I notice when I log it with datamaster when it's cutting out the injector duty cycle goes over 80% and flashes red. Does this mean my fuel pump or injectors need upgraded?

 

Time for some new injectors....

 

Datamaster seems to produce slightly higher duty cycle numbers than seem logical. They do their calculation right, using the "base pulse width".... but it seems like its not unusual for a mildly modified engine to produce DC's approaching 100%, when there is no evidence of a fuel shortage in the way the engine is running.

Do you have any idea what kind of flywheel HP the engine is making? You mention heads, but not a cam.... still using the stock cam?

You mention only at the end that it is 'cutting out'.... under what conditions - engine RPM, throttle position - is it cutting out?

 

I am not sure what the horsepower is, and yes I am still using the stock cam.

The car starts to cut out at 4600rpm and above at 100% throttle. The injector DC is peaking out at around 90%. I don't think its ignition related the plugs, and wires are new and the distributor has only about 2-3 thousand miles on it. The car runs great until 100% throttle at 4600rpm and above.

 

I dont think you ve reached the limits of the stock pump. Probably the injectors. I have a very similar setup to yours (bolt ons+ headwork and stock cam) and im putting 30lbs or 37lbs in mine. But I am also going to run a dry kit so im really going to need the extra fuel. good luck

 

Just for another comparision, with my mods in sig minus the TB, mine was at 100% DC at WOT running the stock injectors. After the 30lb SVO injectors it drop down to 85% DC.

 

Was your car cutting out at 100% throttle with the stock injectors.