starts and stops

[collinandkerry]

2008 d40 have replaced injectors and still have issue
started had rough idle and rough running at 1500 - 2000rm
that has gone but now once been running for a while and driven. when we restart the car it will not idle stalls a few times and if you get it and push the foot down and pump accel it will pick up run a little rough for a sec and blow smoke then all good
it will stop and start all ok
any ideas I was heading toward the SCV poss have pulled out and cleaned before but may be faulty and need replacement

 

[Iceman]

Were the new injectors coded into the ecu properly? Sounds like the ecu doesn't know what is going on. Also check the MAFS. Do a ecu reset as well. Could be an airlock?
Did you do the injectors yourself? I have just done mine and had a similar issue due to the ecu not accepting the new injector codes. Had to get nissan to reflash the ecu with more up to date firmware in the end. Drives like a swiss watch now.

 

[collinandkerry]

injectors were done by my mechanic and were coded to the car
its really a pain to chase as it does not happen all the time but after a run mite do a ECU reset and see what happens

 

[Old.Tony]

I doubt it's an electrical issue because things get better after a bootful. That points to something in the fuel/air system (since that's all that's left!). It does seem like an SCV issue but could also (easily) be air in the system. If it's only really happened since the fuel filter was replaced, that's the first place to look.

To check, put a clear hose on the outlet of the fuel filter, start the engine and look for bubbles in the hose. If you see any, there could be only three real causes:

1) Under or over tightened fuel lines. Both are bad. Clamps should be done up enough to hold the hose and not pinch it.

2) Faulty/misaligned seal inside the filter. There's an o-ring in the middle and it has to align properly to seal properly. Aftermarket filters are much more prone to this.

3) Cracked/hardened hose. Once the rubber starts to harden, it can't mould around the pipe properly and will let air in.

Bad connections/hoses usually also result in poor starting performance in the morning. If that's happened to you, go out tomorrow morning and pop the bonnet before starting, and reach under the filter and squeeze the primer bulb a few times. If it gets firm within 3-4 squeezes you're fine. If it goes past 5 squeezes and hasn't firmed up you've got air in there. It will cause problems like you're experiencing.

There are other possibilities. Turbocharger actuator for one - again, it's hose-checking time (more likely, if it's turbo-related) but the solenoid might also be suspect. We can look at this in more detail later.

Another possibility is the EGR valve. Your best bet is to block the bloody thing off anyway - your engine will breathe easier.