I have a 91 4Runner 3.0 5spd 4x4 the problem is the longer I drive on the highway it has a jerk or a hard miss its like you turn the key off for a second. No check engine light and no codes. I have changed the plugs,cap,rotor,wires,fuel filter and fuel pump relay also added grounds no help. I just did head gaskets,valve job,valve adjustment and timing belt and pulleys it runs great but the "3.0 JERK" not the one behind the wheel. Maybe is it the ECU. Thanks for any help or input, Glenn