Black smoke and lumpy idle, its a very very naughty boy

[R1cho]

The terrano engine that lives in my largo has started being naughty, it started with grey smoke which is now black and has a very lumpy idle, it's not all the time though and i can't see a pattern for when it happens, today while idling it tried to stall, the smoke smells a bit like soot so i'm suspecting over fueling, problem is i have no idea where to start looking on a petrol engine :nenau:nenau

 

[macabethiel]

I assume its well maintained so you have ruled out basics such as clogged air filter, worn or wrong spark plugs, faulty plug leads etc. Cold start enrichment operation - can it be a faulty temperature sensor causing over choking ?

 

[R1cho]

its got all new filters etc. i've not had time to look at anything else just yet, i was just hoping for some ideas as to what it could be to help narrow down my search, i'll give the leads and plugs a look at over the weekend

 

[solarman216]

OK petrol 2.4, struggling to remember now as had 2.7 TDi for long time, so will go through what I can remember although not necessarily in the right order, the fuel pump is in the tank and quite high pressure so on the fuel manifold at the front is a reducing valve that when idling and low power it is supplied with vac so dumps fuel back to the tank, (should be vac on this pipe at idle),, vac pipes in general,, there is a vac controlled swirl flap system in the inlet manifold, vac operator is just visible at rear of inlet manifold again this should have vac at idle,, never had any problems with the injectors but if the fuel filter has not been changed then pos the injectors are bad (dribling),, fuel filter on T2 is under chassis near rear of drivers door pig to change, let me know how you get on, I still have most spares for the petrol, Rick

 

[R1cho]

After a lot of reading and researching, i took a cheap option of blasting some carb cleaner down the air intake and it seems to have made a dramatic difference, the revs have calmed down and the smoke is pretty much cleared, so now i'm going to take the throttle body off and give it a good clean aswell as go round checking all the vac pipes and possibly replacing them

 

[Banshee]

After a lot of reading and researching, i took a cheap option of blasting some carb cleaner down the air intake and it seems to have made a dramatic difference, the revs have calmed down and the smoke is pretty much cleared, so now i'm going to take the throttle body off and give it a good clean aswell as go round checking all the vac pipes and possibly replacing them

Sweet!!!! All for the cost of a can of squirty stuff, that's a bonus

Sent from my SM-G930F using Tapatalk

 

[R1cho]

O.K the black smoke came back along with some erratic behaviour from the revs on idle and when driving, my fuel consumption dropped to 50 miles on £20 of petrol

Anyway i was a fair bit from home and the petrol light came on so i refilled at the next nearest station, which happened to be a tesco, filled up and it drove home lovely, no problems what so ever, no smoke no jumpy revs at idle, turns out the fuel at the local station is a bit iffy and yesterday they had customs in dipping the tanks

any way i've filled up again at tesco and still running fine, must have been the shite fuel from the local station

 

[Blocky10]

Glad you found the problem before stripping things off it and spending money!
It's shocking to think the fuel is that bad it can cause problems, and you still have to pay full price for it!

 

[Banshee]

Know where I stand with a sealed tub of veg, seem to be thorough quality control tests carried out on edible stuff :naughty :naughty