6.5 td optical bump
 

any information on the optical bump? how is it done?

the DS-4 injection pumps uses an optical sensor, that reads a disc inside the pump that measures the timing and fuel. Optical bump is when you move the optic sensor inside the injection pump which fools the ECM into giving it more fuel and timing as the otpic sensor is no longer reading real or actual numbers since it has been moved from the calibrated position. This is a cheap way to add fuel to an electronically injected engine. But i do not recommend it. it makes for touchy throttle, beats the trans, and more. If you want more power get a programmer.