Grenade issues

Grenade is the correct word.
Hope you have better luck than others who had the same problem.
For some it was as simple as cleaning the oxy sensor. Try the Nissan site they would be of much further assistance.

Do you have the long document from the patrol4x4 forum member that details how to fix this?

Pat

This sounds like the ECU is doing the right thing - to a degree! When the turbo overboosts (25psi is way too much), the ECU opens the vanes on the turbo to stop boosting. Normally you do not get an error light/code for this and simply taking your foot off the accelerator cancels the overboost signal and you are back in business. One often sees this as a lack of power, they take their foot off the accelerator and all seems normal again - is confusing if you don't know what is happeneing.

What I do not know is if you exceed the overboost by too much, if this logs an error code/warning light and requires an engine shutdown to reset - from the sounds of your problem, it may do.

Has anyone fiddled with the turbo vane connector rod or max boost adjust screw on your engine? When one blocks off the EGR, the engine now produces too much boost so the boost adjust screw needs to be turned down (I had to do this on my GU). But if someone adjusts this to try and give more boost (equivalent to turning up the wastegate pressure on a 4.2GU), the ECU measures this higher boost pressure and now opens the variable vanes - net effect is a loss of power after a momentary increase.

For my money, I reckon that your EGR valve is sticking (can happen when hot) and resulting in high boost. You could also have a faulty MAF sensor (not unusual) as well. Combine these two problems together, especially if someone has fiddled with the max boost screw and you will have a frustrating, intermittent, problem.

If it were me, I would replace the MAF, block the EGR and if still overboosting then turn down the max boost screw. Until you stop the high boost pressure you will not solve your problem.

Cheers

Captain

doesnt the maf sensor control the elctronic boost on these motors?what kind of air cleaner is being used , the reason i ask is that the maf sensor is an hot wire and if it gets contaminated it sends the wrong reading to the electronic boost