I have been trying (unsuccessfully) to sort out engine running problems in my 93 240. The car always starts fine but begins to shutter and eventually die out after it warms up. It has good compression, I have cleaned the throttle body, changed the AMM and oxygen sensor, replaced ignition components such as plugs cap wires ect..., I have also removed cleaned and checked the function of the two temp sensors located on the left side of the engine. There is no check engine light on, but when I ran the diagnostic procedure I get two codes 1-2-1 (fault in signal for AMM, and 3-1-1 (vehicle speed signal missing). What does this mean???