NO BOOST ON HDI 90

[hywel30]

Heeeelp!!!! can anyone tell me what is up with me pug???
Last week whilst drivin i noticed the turbo wasn't coming in till around 3000rpm....and anything below that was flat as a pancake.
When i got home i first thought the blower was on the way out!! so i decided to start strippin it apart as i have another turbo to stick on it.
on stripping it i noticed a split boost pipe wich had split where i had tapped my boost gauge into. so i replaced this along with fitting the other turbo. Once all back together i took it for a drive......but know it wasn't boosting at all really so i thought perhaps the turbo was shot, even tho it wasn't seized and had less play in the bearings than the original.
So i decided to refit the original hoping it was the split pipe all along that was causing the problem and not actually the turbo.
No i don't think it was Having put it all back together it know starts spot on, idles perfect but has no go what so ever..... it's also only boosting to 10psi not 1bar as it did before???? any ideas before i torch it lol
Just thought i'd mention i have disconnected the EGR and it has been for last 6 months and been runnin fine.

[eoin27]

Up to 3000rpm is where the peak performance comes from the 90. THe turbo usually switches off then and the power reduces. You have the opposite effect which would indicate a faulty turbo unit. You should be able to hear that familiar whistle from the turbo spooling up. If not, then its back to the drawing board. Ive never heard of a turbo on a HDi going before so maybe it wasnt the turbo broken in the first place?

[hywel30]

You can heer it spoolin up no problem, and the gauge shows it comin in at about 1800rpm it boosts to 10psi max!!! but there is no pull at all, you can usually feel it kickin in i know it's not ferocious lol but never the less you can srill feel it....but now ther is nothin, doinf my f..ing head in had the bloody thing off 4 times now can almost do it blind folded in the dark lol

[Welly]

If there's no engine light on then I would be thinking maybe the Vacuum pump is faulty (on the right hand side of the camshaft) but without a proper diagnosis it's dificult to say I think the turbo wastegate is held shut (creating max boost) by the vacuum so if the vac goes it 'fails safe' open to the wastegate. The control solenoids can sometimes play up (have you tried swapping the EGR and Turbo one's around?

Don't go buying stuff in on my say-so though cos I'm only guessing but I would probably start with replacing the vac pump and all the vac hoses cos that's a pretty good treat for the car anyway in the long term

I think you can kinda test how good the vac pump is by pumping the brake pedal till it goes solid and the start the engine (with foot still on pedal) and as the vac builds up the pedal should 'release' down a bit; similarly and with the engine running if you pump the brake like a mad man it should firm up a bit but quickly relax again - if it stays solid for too long then the vac pump is struggling to keep up.

[hywel30]

If there's no engine light on then I would be thinking maybe the Vacuum pump is faulty (on the right hand side of the camshaft) but without a proper diagnosis it's dificult to say I think the turbo wastegate is held shut (creating max boost) by the vacuum so if the vac goes it 'fails safe' open to the wastegate. The control solenoids can sometimes play up (have you tried swapping the EGR and Turbo one's around?

Don't go buying stuff in on my say-so though cos I'm only guessing but I would probably start with replacing the vac pump and all the vac hoses cos that's a pretty good treat for the car anyway in the long term

I think you can kinda test how good the vac pump is by pumping the brake pedal till it goes solid and the start the engine (with foot still on pedal) and as the vac builds up the pedal should 'release' down a bit; similarly and with the engine running if you pump the brake like a mad man it should firm up a bit but quickly relax again - if it stays solid for too long then the vac pump is struggling to keep up.

Engine light has been on since got the car 4 yrs ago m8, gonna check vacuum pipes which is turbo i know which is EGR but that was disconnected months ago.