D22 rev fluctuation

Hey all hopefully someone can shed some light on an issue my mate is having.

The first signs of an issue was when we were installing a turbo timer a couple of times it just stalled we didn't really think much of it.

a few weeks later he complained that as he got up to around 2800 RPM it started to miss and what seemed to be like go into limp mode and loose all power but dropped down a gear and was fine no engine lights or anything

last night we replace the exhaust manifold as it was cracked all the way through i thought this may have something to do with his issues so was not to worried. after we got it all back together it would not idle smooth eg going up and down approx 200 RPM we hit the heat switch and it ran well for about 15 mins then it lost all go and was missing like crazy the whole engine was shaking i actually got quite worried so shut it off

we have cleaned the MAF replaced fuel filter done ecu reset what else could it be?
after searching i see the actuator may be the cause but would it have such an effect just on idol?
i have also seen its possible it could be the suction valve but i dont know much about this part

any input would be great we are both quite concerned

What motor does it have in it? If it is the yd25, I'd look at replacing the suction control valve. That normally causes the issues you are describing. You could try cleaning it, there are a few write ups on the forum about doing that, I would try running a can of liquimoly fuel system cleaner through it first and see how you go after that.

Ah yes should of mentioned that it's a 2008 so jap yd25

So the scv can be cleaned?

Yep. There is a write up on here about doing a liquimoly diesel purge, I'd give that a go first

i can't recall if the yd25 has the neutral position switch.
i would be unplugging that first.

This should help if you haven't found it already
http://www.navara.asia/showthread.php?t=27063