dam diesel

[pagar]

I have a 70 series running a 3b diesel, after a trip down country I noticed a miss fire in the upper revs and was unable to go over 80 kms on the way home, was blowing a heap of the black out the back too. I ran it a few times at home and it idles smooth but when I bring the revs up it starts to splutter towards the top end of the rev range. after checking every thing under the hood including swapping out the fuel filters etc still the same then all of a sudden I rev'd hard it back fired and then came right. then a few weeks later after about 6 hours driving back and forth to Hamilton it started doing it again? I am very puzzled as to what could stop and start causing a miss in a diesel. any help would be great. cheers Stephen

[yorick]

If it's blowing black smoke and not getting to peak revs then the most likely thing is blocked aircleaner or airsystem. Check for restrictions in yer air intake.

The other thing it sounds like is a jammed exhaust brake butterfly but I don't think Cruisers have those do they?

[pagar]

no no exaust brake, snorkle is sucking like mad but I supose could be something beyond filter, filter is clean

[tweake]

leaking injector??

also watch your intake pipes. i don't know if they are plastic/rubber or steel but its been known for some of the plastic/rubber ones to colapse at high rpm.

[cruza]

Could be a injector leaking/not atomising properly at full load, black smoke is unburnt fuel ,weather its over fueling or blocked air in take. inline pumps also have a governor I think, and a advance/retard on fuel pump timing that varies with engine speed . If everything looks ok , pull the injectors and get them tested, if theyre ok . It will be the pump playing up-best left to the experts . Some of their test rigs are pretty good and can identify problems quite quickly, fuel pump repairs always cost $$$ don't take short cuts .Remember there is a strainer/mesh in the fuel tank as well on the 70's and a small mesh filter on the in let to the fuel pump some times.

[KiwiBacon]

I'd start with a DIY compression test. If one cylinder has lost compression then it won't burn cleanly and will just make smoke.

Park it on a hill with the engine off, put it in a suitable gear and slowly let it roll forward, compressing each cylinder. If one feels weak then get it properly compression tested.

[pagar]

Thanks guy's, I have run again and removed air intake and still doing it. So tonight I will remove fuel lines from pump and filter and blow back to tank and see if it is a line blockage. failing that I will pull the injectors out and have them cleaned and tested. will post a coment once done so others may know too. cheers

[KiwiBacon]

Thanks guy's, I have run again and removed air intake and still doing it. So tonight I will remove fuel lines from pump and filter and blow back to tank and see if it is a line blockage. failing that I will pull the injectors out and have them cleaned and tested. will post a coment once done so others may know too. cheers

Black smoke is a combustion problem, blocked fuel lines won't cause that.
Do the compression test before you spend big $$ on the injectors.

[Henry]

Hi

Is your 3B the older one with the Diaghram ( spelt wrong) in the injector pump?

could be that needs replaced???

[pagar]

sorry should have put starts to puff black but then is white grey, I have spoken to a Diesel specialest who said injector pump rebuild more than likely, $700 - $800 (lovely, there goes the front ARB locker...) I will however try blowing out the fuel lines first, also spoke to a guy that does carbon cleaning and he said that if it is a bit of crap in the pump it will clean it out as the back flush the intire injection system from block to filter. (hard for me to accept it is a worn pump as the problem went away for over a month and 6-700 km's and a damaged part cannot undammage) it is however a gamble cause a $200 carbon clean could fix it or do nothing. who knows I cannot decide so I will ask my wife which she wants to pay for and do the oposite..... ( I love to live life ion the edge...)

[Henry]

Hi

Have a look at

http://forum.ih8mud.com/diesel-tech-24- ... ement.html

[pagar]

well last night I removed the fuel lines at the mid truck joiners blew out both outlet and return from tank them blew out from return line back through pump and filter put back and started it up. it ran better but still puffing and spluttering gave it the hell rev and the pluttering died of and she is running clean. still sounds like a very slight miss at wide open throttle no load though, will put through WOF when I finish swapping out damaged front springs and take it for a good hard run. (also I will pull the tank out, replace fuel filter again and cleen out tank and also see if I can clean the pick up filter in the tank, not sure if these trucks have a removable pickup or not) I will post more when I know. I am concerned that it is a case of problem gone temporarily again but cannot understand that if it is the pump at fault it could fail them be fine then fail again and then be right....after all it is not made by lucas or ford.....