Smta Posted December 19, 2018 Share Posted December 19, 2018 Newbie here with macks, we have a 2000mack cl713 e7-427 thats been having a couple issues the past year.. its had an intermittent hi idle and jake brake has been coming and going. the tack bounces around a bit but it used to read around 4-500 at idle but now only drops to 6-700rpm. the first thing the driver noticed was the jake not working so we rebuilt the jakes W/ new seloniods new in dash switch, a couple new wires ends, and updated/hyflow oil pump. then after the report of the idle we got a new electric foot throttle, ours had a flat spot on it.. any thoughts would be help full, we don't have any close shops that can hook to the computer but we may have that next on our list.. Quote Link to comment https://www.bigmacktrucks.com/topic/55090-2000-e7-427-hi-idle/ Share on other sites More sharing options...
Mack Technician Posted December 20, 2018 Share Posted December 20, 2018 Did that fix the Jakes? Quote Link to comment https://www.bigmacktrucks.com/topic/55090-2000-e7-427-hi-idle/#findComment-411649 Share on other sites More sharing options...
Smta Posted December 20, 2018 Author Share Posted December 20, 2018 The Jake's work great once in a while when they decide to come on.. the high idle has me a little more baffled.. and there is no extra lights on In the dash. Quote Link to comment https://www.bigmacktrucks.com/topic/55090-2000-e7-427-hi-idle/#findComment-411667 Share on other sites More sharing options...
Mack Technician Posted December 20, 2018 Share Posted December 20, 2018 (edited) Idle to 900 is usually...... A. Throttle position sensor open/ground/short. Blink 5-1 or B. J1939 communications limited. Blink 6-4 If your engine speed sensors are wigg'in out you should have a code. It's common to have clutch metal stick to the magnet tip of the sensor (flywheel housing mount), that can screw things up. During key-on do you see the amber engine fault light bulb is still working and cycling? Edited December 20, 2018 by Mack Technician Quote Link to comment https://www.bigmacktrucks.com/topic/55090-2000-e7-427-hi-idle/#findComment-411676 Share on other sites More sharing options...
Smta Posted December 22, 2018 Author Share Posted December 22, 2018 Didn't think about dash light being burnt.. will check it out next week also will check speed sensor.. thanx for the ideas.. Quote Link to comment https://www.bigmacktrucks.com/topic/55090-2000-e7-427-hi-idle/#findComment-411768 Share on other sites More sharing options...
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