td42ti 2006 patrol misfire

your getting air in the fuel pump. It causes the timing to jump around.
Easy way to check, run a fuel line from a jerry can straight into the injector pump. if it's gone check your filter system. They can suck air around the primer or the water sensor in the bottom of the filter. If you still have the problem then it's the front seal in the injector pump. They have a 17 mm drive shaft and wear a groove in them. you can just replace the seal if you like or go for a full rebuild.
Cheers

Scott

Get it over to a Diesel specialist.
I just took our 2001 GU 11, to a specialist and the difference is very noticable.
160 k's on the clock
All injectors replaced.
Glow Plugs replaced.
Pump reset.

Dyno tuned

Goes much better, and well worth it

Cheers
Bucky

Had same problem with my 2.5tdi courier, intermittent miss at road speed.
The lint filter in the injector pump was the problem.
Hope this helps.
Bushy

Scott I would definitely check the small gauze filter located below the banjo fitting on the inlet to the fuel pump. They do get blocked and cause a similar problem to which you describe. They don't get a mention in any of the prescribed services and are also difficult to find on the Nissan microfiche for parts. I had a problem with mine some years ago and told the mech that he should check the filter only to be advised there was none fitted. Persevered for a while but eventually had a look for myself and could only see a small spring in the aperture which I removed and had a bit of a prod around with a cotton bud and felt something shift so put a small amount of pressure on it, pulled it out and low and behold, a very dirty and blocked filter. Cleaned it and problem gone. From that time I have carried a spare in the glove box. Certainly worth a try and a cotton bud is a neat fit to remove it with.
Regards,
Ray W.

Mike is right> I forgot about the filter in the inlet. Not all have them.
Easy to tell if you have 1, Just remove the banjo bolt, if there is a spring then you have a filter.
Good luck

2006 TD42ti dont have this filter under inlet fitting - or rather it exists but is located deep inside pump and unservicable

Check the basics as directed here then head to specialist

Thankyou all for your advise been a great help we checked the pump inlet but no filter there ill be doing some more checks tomorrow checking for air leaks before an after pump if i cant find a problem it will be going to uniteds got some advise over the phone from them today. I will let all know what the outcome is.
Cheers all
Scott