Lucky dogg Posted August 19, 2017 Share Posted August 19, 2017 Hey all, I have a 1998 Mack rd 688s truck with a 350 etech motor. The truck has 700,000 miles and is an Oilfield truck pulling a semi dump on a highway project on site (oilfields a little slow). The truck was pulling around a corner empty when the driver said it just died. It did have a small fuel leak on the electronic fuel deal under the chrome plate on passenger side. We took the two Allen head screws out, pulled it out of the motor, replaced the o rings and bolts and fuel leak is now stopped but still refuses to start. We also changed fuel filters and check fuel pump and bled all injector lines. The truck will start on ether but quits immediately after. Any ideas what this could be? Please let me know if there is anyone who had this issue and what it might be. Thanks all Quote Link to comment Share on other sites More sharing options...
fjh Posted August 19, 2017 Share Posted August 19, 2017 (edited) Question Turn the key on ! does the heater fan still run? If not replace the accessory relay under the dash Edited August 19, 2017 by fjh Quote Link to comment Share on other sites More sharing options...
880joe Posted August 19, 2017 Share Posted August 19, 2017 I may be the gear slipping on the fuel pump Quote Link to comment Share on other sites More sharing options...
Lucky dogg Posted August 19, 2017 Author Share Posted August 19, 2017 The heater goes on and it makes a few clicks like it normally does like click click click. Then click click click (I always turn the key and wait 30-45seconds before I turn it over). This thing is boggling my brain. Mack said they doubt it's the ecm but could it be? There senior tech said if it was the ecm I'd most likely not get any smoke and it wouldn't start on ether. Quote Link to comment Share on other sites More sharing options...
Mackpro Posted August 19, 2017 Share Posted August 19, 2017 On that model RD with ETECH. Check for a dent in the engine ecm. If motor mounts are worn/loose and you make a hard turn or off road frame twisting , the ECM will contact the frame mounted fuel filter base and dent the ECM and short it out. Only takes a small dent. This will cause crank -no start issue. If you have another ETECH engine you can swap ECM and see if it starts 1 Quote Link to comment Share on other sites More sharing options...
Mack Technician Posted August 24, 2017 Share Posted August 24, 2017 Hitchcock ending. Quote Link to comment Share on other sites More sharing options...
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