GQ Patrol 4.2D "Pre Igniting"

Brad, have the timimg checked. John

Not sure how the Nissans work but on the toyota there is a fuel shutoff solenoid that shuts the fuel off when ignitioned turned off.

Sounds like you may have a bit of unburnt fuel in there that wants to ignite. Does it keep on going or does it just turn over a kick once or twice.?

Yep, mine (2000 GU 4.2 td) has done it since new. Nissan stuffed around with it several times under warranty, but didn't make it any better. I gave up with them.
Only does it occasionally, giving a hefty shudder for a few seconds after switching off.
My guess is that the fuel shutoff solenoid is not shutting properly, as there should be absolutely no fuel being delivered after electrical power is removed from the solenoid.
Gerry

I heard a story described in detail on the radio one day. It was about a run away diesel on a largish boat when diesel engines were fairly primitive. Without going into the theory of why it happened, the fact is the sump oil was bypassing the rings and ignited on compression. With no way to control this new oil flow the motor raced and would have blown itself up or seized when it burnt too much of the sump oil.

In the story the engine did not have an air cleaner for various reasons and in the panic the teller of the tale said he pulled his daks down and put the cheek of his unmentionable bottom against the intake. 28 pounds of atmospheric pressure is a fair bit but it wont kill you. His got a bruise but the motor stopped for want of oxygen and he saved the day.

I guess the moral of the story is: Leave the air cleaner off and your bleep bare.

owen

I remember two instances with diesel engines, before electrical solenoids were used and you could push a diesel to start it ( now I'm giving my age away). The first was with an Enfield twin cylinder boxer engine that decided to run in reverse. Obviously the governor did not work (this was on a welding plant) and she started reving faster and faster. We turned off the fuel and ran. Fortunately she ran out fo fuel before it destroyed it's self.
The second engine was a Blackstone engine. This engine threw its over speed governor, not the AVR. We also turned off the fuel and ran but before it stopped all the big end and main bearings were stuffed.
So diesel engines must be watched very carefully as the slightest drop of fuel to pass will keep the engine running especially if it is hot.

Not sure what the cause is, but my GQ has done this since I've had it. 2 things I often do to stop it pre-igniting is either lift the clutch slightly while in gear until you feel it starting to grab and switch the engine off, basically a mild stall. The other is bring the engine revs up slghtly ( by 200 or 300 rpm )for a few seconds and switch it off. Don't know why but it seems to work.
My 2 cents..

Cheers,
Russ

I was told by my mate, a diesel guy, that it is a little amount of fuel getting past the pump when the engine is turned off, apparently common on the 4.2.. Michael

Let me know how you get on as mine does it now and then.

Buy a 3.0