Truck running fine...had a new turbo and oil feed pipe fitted 6k miles ago...no problems......but very occasionally i.e. once per month pulling trailer 2k revs 4 th gear etc over boost come- on....so its not a million miles out. Going thro the forum comes up with two contradicting infos. On the forum is posted a Mitsubishi tech article that clearly states its the bottom screw that needs letting out (unscrewing) if you have overboost. (after checking other things first). This lets the veins move more, which changes the flow of the exhaust onto the turbine and hence reducing the pressure. Yet on the forum people have said its the top screw that needs adjusting. Until I'm happy with my gauge is spot on i don't plan to fiddle with any of it but I like to understand whats going on and why first.Ive enclosed a couple of fotos of my screws (!!!!!) and the lower one has too many threads showing ,as expected. Thoughts and thanks Nik
Bild entfernt (keine Rechte)Bild entfernt (keine Rechte)

Anyone....any thoughts appreciated? Ta Nik

Repling to my own question!!!
This is what I understand from the Mitzi bulletin... In neutral with the engine off the VGT lever should rest on the lower bolt....it does on mine. Then when you start the engine the lever should nearly touch the top bolt....mine does this also.. Then when quickly revving the engine in neutral the lever should nearly touch the LOWER stopper bolt....mine doesn't. In fact my lever may go even closer to the top bolt. The boost pressure is then nearly at 22psi unless I feather the throttle. Any suggestions where to look???
Ive included a youtube clip of it happening...ta Nik https://youtu.be/h1vrO3idqWE

I'm having hideously frustrating turbo issues myself, however that btm screw looks too far in to me, none of that would affect your issue of the vgt not backing off - what revs are you going to? Did you change the solenoids at any point? They need to be able to vent to ATM

Thanks Trucktruck been up to me ....over the summer and been working around the overboost using my gauge. Long storey short,every so often the boost gauge would suddenly drop from say 16" to say 8" on a long up hill with a consequence lost of power so i delved deeper. I removed the circlip that keeps the actuator rod on and could feel the Turbo vane arm moving freelly but occasionally a bit notchy. So removed the exhaust manifold with turbo attached ( a bit of a job...never done it before!) . Opened /split the exhaust side of the turbo to find some grit/pieces of rust and soot on the vanes. The turbo spindle feels fine. Ive cleaned it all out and presently rebuilding it. After cleaning the inside everything felt a smoother action. Prob get the manifold/ turbo back on again next week. On my journey Ive now come to appreciate how futile the EGR assembly is. Up to now I simply have it blocked off but now Im thinking of removing it completely for the sake of simplicity.Most of the turbo removal work was removing the EGR assembly.I'll keep you posted Nik

God ...you can tell this isolation shit is getting to me!! Ive had some good success with me truck recently... got a couple of tyres ,pre owned from my local tyre guy, still got loads of tread..£25 each fitted balanced..job done...no sign of unusual wear due to tracking etc
Fuel tank sorted on third attempt....piss easy taking it in /out
Started starting (!) really sh1t...4 new ngk glow plugs ...someone did a poo job before and only replaced three.. they were all knackered...now starts on the button...didny like the look of the miners ones(sent them back)
Oil leak around cam cover sorted ....still a tiny oil leak from down below but i can live with that.
Removed/cleaned and reassembled by the book the turbo. no smoke from the rear,new oil feed pipe and no play in the spindle. Set it up exactly as per mitzy bulletin....runs great BUT still throws an overboost on long big uphills. I clock wise turned the upper bolt by 1/2 turn and it throws the code sooner....otherwise it runs brill...what am i doing wrong. The only mods ive done is a thro exhaust pipe and a egr blank...would that effect the overboost? Go on ...throw a few ideas out there...Ta Nik... a pint of Guinness for everyone when all this Sh is over..

Hey Nik, I've been getting a bit stir crazy too and been spending the week welding up my newly acquired '95 Pug 205! As far as I understand, winding the top screw out will make the turbo spin up faster, winding the bottom screw out will let it spin down faster. With the straight through exhaust you'll *maybe* have a faster exhaust flow speed, so the turbo will spin up a bit faster than it will stock. If winding top screw in doesn't work, winding out bottom screw may help - go too far and the fan will hit the blades and that won't end well! You've got to be certain the actuator arm length covers the entire distance from top screw to bottom - hand vacuum pump/gauge is damn handy for testing this. Adjusting the screws without having the rest of the system spot on is just going to be frustrating, so you need to make sure the Manifold pressure sensor and turbo actuation sensors are working properly. You need a good quality actuation solenoid - I've seen cheapo ones where the arm is swinging back and forth at idle, as if they can't keep up with the duty cycle required of them. Also worth checking the actuator holds vacuum properly - I've had similar problems when there's been a tiny split in the diaphragm.

www.youtube.com/watch?v=M2kDWLv7O4g&t=929s
I'm awaiting Milners reopening so i can order one.

Quote: AD wrote in post #8

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www.youtube.com/watch?v=M2kDWLv7O4g&t=929s
I'm awaiting Milners reopening so i can order one.

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Quote: Nick wrote in post #9

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Quote: AD wrote in post #8

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www.youtube.com/watch?v=M2kDWLv7O4g&t=929s
I'm awaiting Milners reopening so i can order one.

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Milners are back open for Internet orders

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thanks Heathen....I have some vacuum gauges and ill start going over it with a fine tooth comb looking for leaks. I might replace the vacuum circuits. Any idea of total length silicone I'd need? Ill keep you posted of my findings. Nik

To do the whole lot, a couple of meters would probably do it (excluding egr). if you've got a good vacuum at the solenoid, then 1/2 meter would probably cover the turbo circuit alone.

Finally got there!!! Been locked in covit meant i was unable to go to test on my "overboost hill"...Its very flat locally so could finally head into Wales with mee heavy trailer...Long storey short the overboost is fixed. Previously the engine seemed " strangled" above 3k revs. Took the turbo apart, replaced the vane nozzle. ( I had a spare) and removed the soot . Checked the vanes moved very freely. I think i'd knackered the previous nozzle by unscrewing the lower screw out too much. You guys did warn me!. Set all the linkages up as per Mitzy guidelines and bingo.Thanks again to all who helped...Nik