nissan gq diesel rough when starts

glow plugs

If the glowplugs check out ok you may have a very minute airleak in the fuel system which is allowing a tiny bit of air in when left standing. Does it depend on how long the motor has been off?

g day
you might be having probs with the glow plug timer . this seems reasonably common with the beautiful td4.2 (i love dinosaure donks give me push rods any day) try glowing the donk 3 times before starting when cold . if the timer is at fault you can get buy doing this for quite some time with no after effects . (i think the timers a very expencive however not really sure ) A WORD OF WARNING do not replace with a second hand unit. change glow plugs first then if no improvement try the timer . I think its hidden behind the glove box. hope this helps................................................................................. 666toy

I'm not sure if the GQ is the same, but my MQ used to be the same. Turned out that the servo motor on the injector pump that selects off-start-run fuel settings was sluggish. I replaced it and it went back to being easy and smooth to start.

Cheers
John

Gday miss n nissan good chance it could be your injectors leaking into the engine when the engines off as they still have to hold pressure the excess smoke on start up also points to this Good luck & keep cruisin

I'd say air leak.. when I changed my fuel filters and didnt prime it properly, this exact same thing happened..

My HZJ75 does something similar every so often, particularly if it hasn't been started for a few weeks.
I,ve been lead to believe its due to a small air leak-been doin it on and off for about 5 years.

Cheers
Darrin

I'd say glow plugs first. Small air leaks are damn hard to track down. My TD42 used to be rough starting when I was in a hurry or forgot to wait fer the glow plug light to go out.

If you find that the glow plug timer has failed. Don't buy a new one - they aren't cheap. Just disconnect the wiring from the timer and replace it with a simple push button. This push button should be wired into the LOW amp side of the glow plug relay. The other cables that go to the glow plugs themselves are HEAVY DUTY wire. They carry a lot of current.

Just hold the push button in for say 10 seconds and then hit the starter.

Bilbo