New member.

[Mick427]

G'day everyone.
My name is Michael living in Townsville qld.
I am chasing some tips on my "07" D40 STX
Currently I have been having issues with power and dumping lots of black smoke
not all the time but it is pretty constant.
It has been I guess jerking when coasting at the speed limit what ever that may be and if I put my foot down it will dump a load of black smoke/soot.
I just cleaned the actuator that is on the drivers side as it was gunked up with oil residue, now on top of that I drove the car around the block with the vac hoses rearanged as I thought I may have had them around the wrong way, I didn't have any boost and the car ran slow but it was smooth and no jerking.
Now I have the vac hoses on in there original place and while I have im presuming 100% power back I'm still getting a bit of black smoke and the occasional jerking. But since I have done the clean and check on the actuator and vac hoses it seems to be running better with more power and less smoke
Yet still the occasional dump of smoke and jerk. Any advise would be appreciated. Cheers Mick.

 

[Old.Tony]

Welcome to the forum.

I'd run a bottle of Liqui Moly Fuel System Cleaner/Conditioner through it. Could be the SCV on the fuel pump, the Liqui Moly might give that enough of a clean to fix it. If not, pop the SCV out and wash it in petrol, rinse in clean diesel before reinstallation unless it's damaged, which will cost about $240 from a Nissan dealer to replace it (plus labour if you aren't doing it yourself).

The other thing it could be is the turbocharger vac solenoid. This is attached to the intercooler's intake sort of below the alternator (vac hose goes from the turbocharger actuator straight to it). The solenoid is supposed to oscillate at around 100Hz and move the actuator but there have been lots of reports of this not working correctly. Check that it's not an electrical fault (dirty connection, from water crossing or pressure-spraying the engine bay) by disconnecting and reconnecting it several times to clean the contacts. Output can be monitored on an oscilloscope and should vary even at idle in response to the varying fuel flow (fuel rail pressure should be varying constantly, even at idle).

 

[Mick427]

Cheers for that mate. I did run some liquid moly through it about a week ago which was my first step, I will have a look at the scv this arvy and see how I ho with that. Cheers for the advice.
I will let you know how I go.

 

[Mick427]

Ok update time. Ha ha
I have run some liquid Molly injector purge through and no result I'm sure once I get to the bottom of it my injectors and fuel system will be super clean hahaha.
I had the car serviced and they ran a diagnostic on it and recieved no errors . :-/
There idea is an injector is fouling, but no hard starts or rough idling. So me thinks injectors are fine for now. One of the turbo vac hoses was shonky replaced that and have full boost
But still lagging. So spoke to a injector/fuel pump specialist so to speak and told me check my fuel filter. Replaced that power and lagging has pretty much gone but still every now and then surges and lagging. Now after throwing $600+ at it need to look at replacing the vcv as the bloke told me it is most likely the problem. So I will replace this and plus I will replace the little vac valve connected to the turbo vac hoses. Once I do this I will post again but will be after Christmas as F it beer and presents are more important.
Any ideas would be appriciated.
Cheers for any advice.
And Merry Christmas in advance.