Diesel injector problems

[macandmoss]

Did the usual stupid thing and leant my mini digger out to a friend , came back knackered. My friend who is a mechanic took a look and said he thought I was lucky , swapped injectors round as pot two was the one causing the problems ,the problem followed the injector on all three pots ,took it to a well known place to have it reconditioned and new jets Tec , got it back and my friend fitted it same problem occurred took it back today to check and retest , said it was fully working and showed me on the test bench ,my mate isn't free for another week . Any idea of the problem or what a novice like me can test or try ...thanks ian

 

[Bill Edwards]

I would (again) move it to another cylinder. I don't know what might be wrong with the injector but it certainly sounds like the injector was the problem before it was sent in for repair and although it seems fine on the bench I think it still has a fault.
So move it again to make 100% certain that it is that injector at fault (because if there's one thing I have learnt from being a mechanic it's that you can't trust anything to be working properly, and unrelated faults can and do appear at the same time as diagnosing or fixing others).
If the problem again moves to another cylinder then it has to be the injector - moving it rules out the injector pump, compression etc.

It could then become a nightmare for the injector specialist but if you can be 100% certain that it is the injector then you know to tell the injector specialist that there is certainly a problem with that injector.

 

[normspanners]

Did you clean the system ?? probably water in the system it will kill injectors, it may not be the same injector.

Feel the exhaust manifold and see which pot is coolest then if you slacken off the pipe to that injector and run the engine and it stays the same, that is the bad cyl if the engine slows further that is not the bad cyl,
I did the same last week with my disco, it took ten seconds to diagnose and three hours to get the injector out !
Also you can get the inside of the injector pipes de laminating and the bits block the injectors so if that is happening it will keep happening

 

[macandmoss]

My friend cracked the pipe off on the injector that was reconditioned and problem stopped , tightened it an was back misfiring , same on every cylinder he tried it

 

[the snooper]

My friend cracked the pipe off on the injector that was reconditioned and problem stopped , tightened it an was back misfiring , same on every cylinder he tried it

if you crack an injector and there is a change in sound it usually indicates that cylinder is firing, so if it was the same on all cylinders is there a chance someone put bad fuel in it ?

 

[normspanners]

??? how could it stop missfiring with injector cracked that makes them misfire ??
that is the whole idea of that diagnosis

 

[macandmoss]

Thanks Bill that's why I took it back today as my mate tried it repeatedly before and after recon ,they wouldn't have it and said it was fully working with nice vapour spray , looks like I might have to sear h for a new one

 

[normspanners]

the only time an engine sounds better with injector slacked is if that injector is stuck wide open and it is diesel knocking or the inlet valve is held open by a tight tappet and it is partial firing into the inlet manifold and you get an inlet 'POP'

 

[macandmoss]

No a mechanic just watching ,whatever he cracked it stopped smoking and misfiring as it was

 

[macandmoss]

Would that happen on each cylinder tried , sounded like a knocking to me and struggled and smoked like hell

 

[normspanners]

SAME question did you clean the system ??

 

[normspanners]

sounds like water in fuel and its getting to all the injectors

 

[the snooper]

Would that happen on each cylinder tried , sounded like a knocking to me and struggled and smoked like hell

take the diesel filter off and empty into a clear container could well be bad fuel

 

[macandmoss]

Was rust when injector was done , he said there might have been damp in the fuel ,only just topped it up but it's not new diesel it's last year's , will go and drain the tank down tomorrow , only gets used occasionally

 

[the snooper]

Was rust when injector was done , he said there might have been damp in the fuel ,only just topped it up but it's not new diesel it's last year's , will go and drain the tank down tomorrow , only gets used occasionally

sure sign of water in the fuel

 

[macandmoss]

Should I stick some white diesel in or is red ok while testing ,got some additive to stick in ,and will have the remaining injectors done when I get some cash

 

[Spark plug]

Drain all the fuel and change the filter then run it for preferably under load for at least 30 mins then see ware you are. These small engines don't use much fuel so it takes a very long time to get all the old fuel out the system. Even if you just track it arround for a while it's much better than just ticking over.

 

[Spark plug]

Should I stick some white diesel in or is red ok while testing ,got some additive to stick in ,and will have the remaining injectors done when I get some cash

Red or white dosen matter as long as it's fresh and clean, If your unsure go to the garage and get some white it may save a lot of head scratching in the long run.

 

[macandmoss]

should I stick the injector additive in or wait till its running right

 

[Spark plug]

should I stick the injector additive in or wait till its running right

It wouldn't hurt.