Active Fuel Management, or AFM for short, refers to cylinder deactivation. GM uses it to shut down cylinders under light load conditions to improve fuel economy with their V8 engines. However, Jasper Engines & Transmissions has determined the AFM system can cause some issues with the engine over time.
“In researching this engine, we found that most of the cores coming in had collapsed lifters,” said JASPER New Product Development Group Leader Brad Boeglin. “The collapsed lifter is the effect, but not the root cause of the failure. The root cause can be mistimed command events from the ECM, oil viscosity, oil temperature, restricted orifices in the LOMA board, and low oil pressure.”
JASPER uses a press to install cam bearings on all of JASPER’s remanufactured LS & LT engine platforms to reduce distortion or bearing damage, and each engine goes through an extensive cleaning cycle. “This takes care of two root causes. However, JASPER cannot do anything to correct the command from the ECM or the oil viscosity,” said Boeglin. “For this reason, JASPER’s developed and released an AFM-delete engine that removes the system entirely. We replace the original cam with a non-AFM version, remove AFM lifters, install all standard lifters, and remove the AFM solenoids.”
With the AFM hardware parts removed from the engine, installers must modify the vehicle’s ECM so it will not set codes or try to command the AFM system, which would shut off spark and fuel to the cylinders. “A tuner is supplied with every AFM engine, allowing the installer access to the ECM and modifying the AFM system,” said Boeglin. “JASPER has instructions to help walk installers through the process.”
With internal changes to the AFM-Delete engine and ECM modifications, JASPER has noticed a half to one and a half-mile per gallon reduction in fuel economy. “It depends on the amount of city to highway driving the customer does with the vehicle,” Boeglin said. From an emission standpoint, the GEN IV JASPER AFM-Delete engine has gone through the California emission testing process and received a CARB executive order # D-391-1, which allows it to be legally sold in all 50 states. “The GEN V version is currently 49 state compliant, and we are actively working on obtaining a CARB EO for that version too,” added Boeglin.
For more information on the AFM-Delete engine and the complete line of JASPER remanufactured products, log onto jasperengines.com, or call 800.827.7455.
Click on the video link for further detailed information…https://youtu.be/ANGJQr1N6ic
