still cuting out not boost cut

[greeleyt5]

hello everyone, well im still geting cut out under hard accelaration and i dont think its boost cut now, i have whiped the plugs out this morning they are all ok, i replaced the leads not that long ago less than 5000k and i have fitted a tim boost gauge this morning to find out exacly whats going on boost wise and she is boosting at 0.8 bar so im pretty sure its not boost cut, if i set off from a standing start at give it some welly shes fine boosts and accelarates as she should but if i am traveling along say 30mph or so and then boot it, it kicks down a gear or two and then starts to accelarate but then i just loose all power for a split second like boost cut or a missfire then continues to accelarate with no problems at all, when she does cut out it is quite violent and not really like a missfire, if i turn the boost right down on the mbc so i hardly have any boost again shes fine but p**s poor accelaration, its boost related i would say but im just scratching my head once again, it has only done this since the new turbo has been fitted, with the old turbo i could crank the boost right up with no probs what so ever, could it be possible the turbo unit is faulty in some way as i presume 0.8 bar is around standard i dont like keep doing this as shes my pride and joy but thats the best i can explain whats happening, any help or ideas please guys and a big thanks in advance.

[AndysR]

hello everyone, well im still geting cut out under hard accelaration and i dont think its boost cut now, i have whiped the plugs out this morning they are all ok, i replaced the leads not that long ago less than 5000k and i have fitted a tim boost gauge this morning to find out exacly whats going on boost wise and she is boosting at 0.8 bar so im pretty sure its not boost cut, if i set off from a standing start at give it some welly shes fine boosts and accelarates as she should but if i am traveling along say 30mph or so and then boot it, it kicks down a gear or two and then starts to accelarate but then i just loose all power for a split second like boost cut or a missfire then continues to accelarate with no problems at all, when she does cut out it is quite violent and not really like a missfire, if i turn the boost right down on the mbc so i hardly have any boost again shes fine but p**s poor accelaration, its boost related i would say but im just scratching my head once again, it has only done this since the new turbo has been fitted, with the old turbo i could crank the boost right up with no probs what so ever, could it be possible the turbo unit is faulty in some way as i presume 0.8 bar is around standard i dont like keep doing this as shes my pride and joy but thats the best i can explain whats happening, any help or ideas please guys and a big thanks in advance.

If it's only done it since you changed the turbo I'd be checking the preload on the actuator and the vac lines to and from the turbo as they would be things that could be at fault.

[greeleyt5]

hi what do you mean by preload on the actuator and how do i test this i have checked all the pipe work and it all seems fine and secure

[AndysR]

Is the pipework the right way round? Preload is the amount of tension the actuator is putting on the wastegate. It's what you would adjust to run less or more boost if the actuator has become weak...

[greeleyt5]

Is the pipework the right way round? Preload is the amount of tension the actuator is putting on the wastegate. It's what you would adjust to run less or more boost if the actuator has become weak...

yes mate all the pipe work is right i also have a t5 estate that i checked everthing against it to make sure its right, i changed the actuator when i did the turbo and the new one is/was alot tighter than the old one to move and i have adjusted the thread to roughly the same length, ive just been out for a run in it and turned the boost down and it doesnt cut out/miss but hardly has any whoosh to it at all and its boosting to 0.6 bar now if i turn it up any higher i get boost cut/stall, its like the turbo just isnt up to the job is it possible the turbo just isnt as good as my old one both td04 15g.

[Yorkshiresxi]

Take the ECU out of your other one and try it in this one...then you can rule out a knackered ECU...

[greeleyt5]

Take the ECU out of your other one and try it in this one...then you can rule out a knackered ECU...

yeh i have already swaped them as the one in my saloon was meant to have a remap, so just to see if it made any difference in the estate but it didnt, and yes i was still geting boost cut on my saloon with the other ecu fitted.

[Rnash2002]

I would get a new set of volvo plug in her and make sure the gaps are spot on aswell.

[Ed.]

I would look at changing the distributor cap and arm if they haven't been done recently.

Ed

[greeleyt5]

Quick up date guys, I have found the problem cause of my boost cut it was the mbc that was faulty I have removed it and turned it up slightly on the actuator and now it's fine it boosts well at 0.8 bar and holds there no problem at all. I thought it was very inconsistent some times it did it, sometimes it didn't, well problem solved I'm a happy boy now.