I live on the banks of Cahora Bassa in Mozambique so a lot of unusual stuff crosses my workshop floor so when the local fish farm called me and said their Cat 360B Telehandler would only idle. The local foreman . a difficult obnoxious Frenchman was yelling in my ear how the machine stopped working , I was seriously tempted to be rude back to him. The story goes that it ran out of diesel and when refueled and presume primed it ran for a few hundred meters and went into idle mode .It was late in the afternoon and had a peak at the obvious , pulled the codes and found one active code which was open circuit fuel sender, Not surprised but not disabling either.Thought I would sleep on it and popped around the next morning to find the bloody Frenchman had removed the fuel tank even after I had told him that there was no dirt in fuel and it could not be the problem. A logical approach is vital to good diagnosis and substitution of parts is not an option. Block the noise from all the experts around you and follow a logical approach . Everyone said diesel fuel issue but in my mind the problem was electronics which is my game. Temperature in the high 40's sweat running into your eyes and thinking if electronic why no fault codes. Had a look a schematic to see what controlled the injector pump and saw a can bus from ecm . Hauled out the fluke scopemeter and looked at the can bus and was amazed . As it started perfect comms and then ecm seems to hang comms stop and engine idles and nothing else . Back in my programming days something came back to me . Never interrupt an interrupt and put my scope on the throttle 1 input to ecm . Perfect PWM signal from throttle but then I looked again and as soon as I hit the starter there was just random noise on scope.The engine harness runs past the starter motor and on careful inspection the signal wire after 15 years of use would short to starter motor case under engine vibration but be okay if engine not running. The ecm was trying to service the noise in its throttle reading interrupt routine and ecm was crashing . A bit of tape and some zip ties and problem solve, What did I learn . Be logical and ignore all the advice from the peanut gallery.Test and don't guess. Good practice not to have replacement parts or the ability to fire the parts cannon. Keep the discipline and remember life is not supposed to be easy
No replies yet.