merc engined cherokee

[chrisbrad66]

Hi all, the wifes got a Jeep Grand cherokee with the merc 2.7 diesel in it, it has started to puff black smoke on idle and very low revs, not constant smoke just rythmically like its only one injector faulty, it idles great not lumpy or anything, how can i check which it is or if it's anything else causing it? its a 2003 plate by the way.

 

[BlackC55]

Check for a boost leak. Listen for hissing air under load

 

[chrisbrad66]

Thanks i'll have a look in the morning, by the way i heard the egr valves clog on these? are they hard to remove and clean?

 

[chrisbrad66]

Had all the intercooler hoses out today, all ok i pressure tested the intercooler, thats ok, i cleaned the egr valve and inlet manifold, checked the turbo endfloat and all connectors to injectors and sensors everything looks fine, but still it smokes on idle and low revs, any more ideas please