B4001 (Injector Flow Rate) - accurate # required?

[Boost]

Table description says:

"Flow rate of the fuel injectors. [in Lbs / Hour, referenced to Manifold Vacuum PSI (GM.MANVAC)]
If the fuel rail pressure is NOT referenced to manifold pressure, then decreasing the manifold pressure has the same effect as increasing the fuel rail pressure. The fuel flow rate of the injectors will increase at higher manifold vacuums (i.e. lower manifold pressure)."

Is there any reason to input a value here that is NOT the actual exact size / flow rate of the injectors installed?

What would happen if for some reason a much bigger number were entered?

[Jetmech442]

From what I've seen, this table (and it's buddies) is responsible for Probly 75%of issues. If you have a vacuum line on your fpr, then this should be a flat line. If no line then it should slope. Having this and the other tables like small pulse adjust, offset, voltage correction etc, are critical to have exact because calcvet is making its decisions based on this being dead on.

[joecar]

B4001 should have the correct actual flowrate that matches the measured rail pressure.

The exception to this is when boost is causing the LS1 MAF internal limit of 512 g/s to be exceeded, in which case you have to scale the IFR, VE, MAF down (by the same factor)... in this case the IFR error is intentional and is compensated for in the scaled VE and MAF.



If IFR is bigger than actual, then PCM opens injector for less time (since B4001 says injector flows more), so less fuel is sprayed, so it will be lean...

until trims get involved and correct fueling to stoich.

[Boost]

Thank you both!! Let me check a few more things..