Big Rig Posted September 24, 2012 Share Posted September 24, 2012 Hi I bought an old 1985 R model Mack truck last year and it ran good but recently it has started smoking blue smoke, it had a miss in it so I changed the number 1 injector spray nozzle but truck is still smoking but not as bad can it be my fuel injection pump or something else? Would really appreciate some advice! Quote Link to comment Share on other sites More sharing options...
farmer52 Posted September 24, 2012 Share Posted September 24, 2012 Blue smoke is oil. Could be a stuck ring, bad turbo seal, or valve guide/seal. The fuel injection pump is oil lubricated. Quote Ken PRR Country and Charter member of the "Mack Pack" Link to comment Share on other sites More sharing options...
mowerman Posted September 25, 2012 Share Posted September 25, 2012 welcome..and good luck..bob Quote Link to comment Share on other sites More sharing options...
slpwlker Posted September 25, 2012 Share Posted September 25, 2012 Welcome to the jungle Quote Link to comment Share on other sites More sharing options...
oilburner Posted September 25, 2012 Share Posted September 25, 2012 Hi I bought an old 1985 R model Mack truck last year and it ran good but recently it has started smoking blue smoke, it had a miss in it so I changed the number 1 injector spray nozzle but truck is still smoking but not as bad can it be my fuel injection pump or something else? Would really appreciate some advice!Does it smoke all the time or just when it cold, does it have blowby it could be low compresion or more injectors. Quote Link to comment Share on other sites More sharing options...
Lmackattack Posted September 25, 2012 Share Posted September 25, 2012 yea smoke can be so many things. Is it low on power? you can have bad valve guides, turbo seals, incorrect pump timing, bad injector(s), bad injection pump, worn rings, cracked piston, etc.... best way is to do some basic tests on the engine and pump and hopefully.... or not..... you will find the clue. If these tests dont give you any ideas and if you have time pull the exhaust manafold and see if any of the ports are wet with oil. Quote Link to comment Share on other sites More sharing options...
theakerstwo Posted September 26, 2012 Share Posted September 26, 2012 Also old fuel can make one smoke.I over hauled a 8V92 one time to find out he still had some fuel in it that came from south of the border. Quote glenn akers Link to comment Share on other sites More sharing options...
staxx Posted September 26, 2012 Share Posted September 26, 2012 If it smokes all the time try doing a cylinder cutout test with truck running a idle crack each fuel line loose at injection pump one at a time to see which cylinder is causing the smoke and miss be careful fuel is under pressure and will make a mess, get the problem narrowed down to which cylinder and we will go from there, Quote Link to comment Share on other sites More sharing options...
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