fuelsaver

had the same thing on a rb688s bad engine position sensor at the bell housing wire was rubbing on the clutch arm and causing a dead short and no accelleration,replaced the sensor and no problem since.

Hello everyone i am new here and looking for some help and to find out if this is a comon problem on these trucks. i have a 2003 rb688s truck with an e7 engine While driving the truck down the highway or city streets the throttle will soose response and go to idle for about ten seconds or so.Or if your sitting at the lights ready to make that left hand turn the throttle will not respond (just goes to idle.....engine never shuts off and no engine light) then it will come back and a way we go. We have scanned the engine for codes. found low coolant sensor code and #5 and #3 unit pumps. we replace the coolant sensor replaced both unit pumps replace the engine position sensor just in case. replace the throttle pedel assembly and check wiring up under the dash for cuts or grounding out. check wiring from the ecu to the cab. set top end of the engine. checked the wiring from the coolant level sensor to the ecu...Note ecu is located on the left side of the engine.. no rotted wires or pins...very clean at both ends. The only time now we see the engine light on is first thing in the morning while the ecu is testing it. i am thinking it maybe a bad ground or power feed to the cab..but the gauges and lights never flicker. we have replace fuel filters and done complete service in the past week. thought it may have been the jake brake or cruise switches so we dissconnected the wires from the switches and drove the truck around with still the same problems onething to note when the truck was new at around 50000 k/m the first engine blew a rod out the side of the block......then around 90000k/m the second engine blew up......both replaced under warranty....but now 7 years latter and 450000k/m more we have this little problem. any help or suggestions would be great thanks in advanced have a great day.