tommac Posted July 6, 2009 Share Posted July 6, 2009 Hi all- any suggestions greatly received onthis! A friend of mine has a disco 300tdi (96 on an N) Had been stood for some time (12 months) and now has a really bad missfire- all through the rev range but really bad at around 2k rpm. changed injectors so not them- changed fuel filters- all ok lift pump appears ok- checked tappets.....run out of ideas! Quote Link to comment Share on other sites More sharing options...
errol209 Posted July 6, 2009 Share Posted July 6, 2009 Hi all- any suggestions greatly received onthis! A friend of mine has a disco 300tdi (96 on an N) Had been stood for some time (12 months) and now has a really bad missfire- all through the rev range but really bad at around 2k rpm. changed injectors so not them- changed fuel filters- all ok lift pump appears ok- checked tappets.....run out of ideas! Stale diesel fuel? Water in the fuel system? Air in the fuel system? Damp or mice or oil in the ECU wiring? Quote Link to comment Share on other sites More sharing options...
cipx2 Posted July 6, 2009 Share Posted July 6, 2009 Any functional/mechanical reasons it was abandoned 12 month ago? Did the owner run it on cooking oil or alike? Did you bring it to op temp and see what else seems to be wrong? Overheating signs, coolant issues, oil in coolant or vice versa, bubbles in coolant etc? What about smoke (on start up, idle, high revs under load/no load? Did you try driving it around and put some load on the engine (pedal to the metal)? After you make sure the fuel is right, no air etc, you can undo the inj pipes one at a time to see if it's one particular cylinder with problems or its a random misfire. A compression test would be another thing to do. Quote Link to comment Share on other sites More sharing options...
tommac Posted July 7, 2009 Author Share Posted July 7, 2009 Thx for reply- it has been sat on his driveway- he has been away with work hence not used. Did sling a can of diesel in it but could be water or simialr i guess! No smoke (well no more than you expect from a diesel) Had it up to temp- drove down our private lane and just the same. Did crack off each inj pipe and all 4 have a similar anount of fuel coming out and produced same result in sound etc. No signs of coolant/overheat probs- I guess compression test is nect then! Quote Link to comment Share on other sites More sharing options...
boyt Posted July 10, 2009 Share Posted July 10, 2009 Thx for reply- it has been sat on his driveway- he has been away with work hence not used. Did sling a can of diesel in it but could be water or simialr i guess! No smoke (well no more than you expect from a diesel) Had it up to temp- drove down our private lane and just the same. Did crack off each inj pipe and all 4 have a similar anount of fuel coming out and produced same result in sound etc. No signs of coolant/overheat probs- I guess compression test is nect then! I would do compression test, at least then you know its ok or not. also had the same problems on the merc vans, early sprinter, the customer would leave it parked up with no fuel in it, then try using it and ran very ruff. the out come was the pump was seizing up due to not having fuel in it keeping it lubed up, the advance shaft would seize, or the bob weights . but you did get 200rpm in the rev range were it ran ok, just a thought andy Quote Link to comment Share on other sites More sharing options...
nicedayforit Posted July 10, 2009 Share Posted July 10, 2009 Hi all- any suggestions greatly received onthis! A friend of mine has a disco 300tdi (96 on an N) Had been stood for some time (12 months) and now has a really bad missfire- all through the rev range but really bad at around 2k rpm. changed injectors so not them- changed fuel filters- all ok lift pump appears ok- checked tappets.....run out of ideas! Does "changed fuel filters" include cleaning out sedimentor? Fuel line air leak. Quote Link to comment Share on other sites More sharing options...
TheRecklessEngineer Posted July 11, 2009 Share Posted July 11, 2009 Have you looked under the bonnet? Seriously though, can you isolate the cylinder that is missing? Or is it running lumpy on all cylinders? Quote Link to comment Share on other sites More sharing options...
treebloke Posted July 11, 2009 Share Posted July 11, 2009 lift pump appears ok- I would change this for one you know is definately ok. Quote Link to comment Share on other sites More sharing options...
tommac Posted July 14, 2009 Author Share Posted July 14, 2009 have cleaned sedimentor and replaced fuel filter. Cant isolate which cylinder currently Lift pump pumps well and can be primed up well- fairly certain its not that...but will swap for the one on the defender to check. Quote Link to comment Share on other sites More sharing options...
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