Incorrect Reported Injector Delta Pressure of 74 psi
I am getting a Cobra Replica registered and need to pass the Australian NSW Emissions test.
The vehicle has a Chev LSA Crate motor, and a Chev Performance E67 LSA Controller. I have worked toward MAF calibration but consistently are getting a very rich mixture at the O2 sensors.
I measured my fuel pressure and it was 60 psi at the regulator. The fuel pressure gauge I have on the dash also read 60 psi (its sensor is located at the fuel rail). That was with the vacuum line to the regulator removed and plugged. Replacing the vacuum line with the motor still running dropped the Fuel Rail pressure down to about 50 psi, both at the regulator and dash gauge. That is what I would have expected under normal conditions.
I have added Injector Delta Pressure as a Channel. Throughout the fuel pressure test it hovered around 74 psi and then 65 psi when I turned the motor off? This can't be true but I can't see why it is so high. The vacuum connection is correct and should maintain a constant pressure across the injectors throughout manifold vacuum and boost. It should be around 60 - 65 psi.
My other issue is being able to meet the Emissions Test requirements. The recent test had high CO levels, and a lean mixture at the exhaust (also showed on my Pro link AEM 30-4110 wideband). A lean mixture and yet the fuel trims were negative and over 10%. I have carefully tired to calibrate the MAF using the Wideband but the fuel trims on Closed loop are very rich. The MAF is situated in a S shaped intake and there may be some turbulance occuring.
I will do a separate post for the Emissions test issue with the results and a scan during the test. For now I would just like an answer on the Injector Delta Pressure. I attach a recent road based scan and the pressure test scan.
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