2002 Chevrolet Corvette Z06: Injector Flow Report
February 26, 2010
What you see above is a flow report from RC Engineering of our longterm 2002 Corvette Z06's injectors. Not only is it a converted scan of a fax of a fax, but it looks like a bunch of alphabet soup. Here's a translation:
Our injectors were in pretty good shape.
Recall, Bothwell Automotive's diagnostic work suggested that a bum injector or two was causing a lean condition and making the engine ping.
The left column in the table above lists the flow of each injector on RC Engineering's flow bench rig, which applies a current to open the injector and delivers a pressurized test fluid for a specified amount of time. The fluid's volume is measured to determine the injector's flow rate. Here, the worst injector was only down about 5%.
After cleaning the injectors, RC re-checked the flow (right column) and they had all come up to spec (260 cc/min).
I'd love to be proven wrong when Bothwell reinstalls these injectors on Monday, but I'm skeptical that the cleaning process will solve the detonation issue. Even if the four worst injectors somehow managed to find themselves in same cylinder bank, it'd only be 4% lean on that bank and not the 14% reported earlier by the ECU. This suggests to me that the MAF is underreporting the actual airflow.
But I was wrong about the knock sensor TSB thing being the culprit, so don't listen to me.
Jason Kavanagh, Engineering Editor