number1trashman Posted January 3, 2023 Share Posted January 3, 2023 Unit 103 no start.docx We have a Mack refuse truck with an MP-7 engine which will not start. Please read attached file showing what we have done so far. Any help is appreciated. Quote Link to comment Share on other sites More sharing options...
0 Onyx610 Posted January 3, 2023 Share Posted January 3, 2023 First let me applaud you for the excellent write up of the issue/diagnostics/and numbers. One quick question before a few of us assist you with this. Do you happen to have any power steering issues? Quote Link to comment Share on other sites More sharing options...
0 number1trashman Posted January 3, 2023 Author Share Posted January 3, 2023 None have been reported. Quote Link to comment Share on other sites More sharing options...
0 number1trashman Posted January 3, 2023 Author Share Posted January 3, 2023 One other point. We tried some starting fluid a couple but nothing. Not firing with starting fluid is odd to me. It seems to me it would at least fire but it did not. Quote Link to comment Share on other sites More sharing options...
0 Onyx610 Posted January 3, 2023 Share Posted January 3, 2023 Have you tried removing egr cross over tube and trying to start it? Quote Link to comment Share on other sites More sharing options...
0 Mark T Posted January 3, 2023 Share Posted January 3, 2023 If it didn't run (or attempt to) on starting fluid, you likely didn't spray enough in.....so best to forget about the starting fluid. Nothing is goin to be proved by running it on starting fluid that you don't already know. Quote Link to comment Share on other sites More sharing options...
0 number1trashman Posted January 3, 2023 Author Share Posted January 3, 2023 The following is how the problem came on: The truck was running fine through the prior week. On Monday the driver started the truck, and it ran for about five minutes and then began to blow black smoke and run rough. When the mechanic got to it, he started it a few times with the same result and then the truck acted like it was running out of fuel and quit. It now tries to start but will not. Quote Link to comment Share on other sites More sharing options...
0 Onyx610 Posted January 3, 2023 Share Posted January 3, 2023 Is the truck deleted? Quote Link to comment Share on other sites More sharing options...
0 number1trashman Posted January 3, 2023 Author Share Posted January 3, 2023 EGR crossover disconnected not change. Quote Link to comment Share on other sites More sharing options...
0 Onyx610 Posted January 3, 2023 Share Posted January 3, 2023 Well for one I bet your doc/dpf is face plugged. That will keep it from starting. Quote Link to comment Share on other sites More sharing options...
0 number1trashman Posted January 3, 2023 Author Share Posted January 3, 2023 It is not deleted, it is California Certified. Quote Link to comment Share on other sites More sharing options...
0 Onyx610 Posted January 3, 2023 Share Posted January 3, 2023 Mackpro is here so I’m gonna wait and see what he thinks. He really is a Mack pro Quote Link to comment Share on other sites More sharing options...
0 number1trashman Posted January 3, 2023 Author Share Posted January 3, 2023 The DPF was baked in May 2022. We took the exhaust loose no change. Quote Link to comment Share on other sites More sharing options...
0 Onyx610 Posted January 3, 2023 Share Posted January 3, 2023 Run a compression test through PTT and see what it comes back with. Quote Link to comment Share on other sites More sharing options...
0 Mackpro Posted January 4, 2023 Share Posted January 4, 2023 Seen lots of cracked/split injector tips in the MP7s of that era. Compression blows back up through the injector and blows the fuel out of the fuel galley. Rarely see it with the MP8’s though. You can possibly take the fuel inlet line off the LH side of the cylinder head and crank over and see if compression/fuel blows out of head. We would check the injectors while we had them out. Looking at the tips carefully with a large magnifying glass. Also , we would get a rubber tip blow gun and while wearing rubber gloves, put thumb over one hole ion the side of the injector body and blow air in the other hole opposite and the crack will sometimes show. 1 Quote Link to comment Share on other sites More sharing options...
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number1trashman
Unit 103 no start.docx
We have a Mack refuse truck with an MP-7 engine which will not start. Please read attached file showing what we have done so far. Any help is appreciated.
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