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I was trying to trace the cause of a noticeable loss of torque around 2000 rpm, and had connected the VNT solenoid pipes together to eliminate control problems. That’s not a good idea though, you get massive over-boost even at 2000 rpm, and strange noises from the turbo; followed by limp mode. I’ve since fitted a boost gauge which is quite good for diagnosing boost problems as you can see the effect of the VNT system working in real time. Mine looks a bit sticky, or possibly just slow to operate. I don’t think that is the cause of the problem, but since it’s intermittent and I can’t be looking at the gauge all the time it’s hard to be sure.
 

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Discussion Starter #22
Can I use Vnt solenoid from 147 1.9jtd 88kw to test on my gt 1.9 Jtd 110kw?
 

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Discussion Starter #24
About new ecu, I need just ecu or something more,for example new key,fuse box etc ?
 

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Yes u can but most likely the vacuum pipes are cracked some parts are made from a hard plastic and with engine heat they crack and start leaking easy to replace yourself, junction box is under intake manifold on top of starter, replace them all if 1 goes the rest will follow pipe is cheap
 

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Sounds like it's overboosting. Possibly a sticky turbo VGT vane. You really need a vacuum pump to test this. The cheap £15 Chinese Mityvac clones on eBay are fine. Plug into the vacuum actuator on the turbo, and pump up the vacuum. The actuator arm should move smoothly forward as you increase from 0-about 17ins.Hg, and then return smoothly when vacuum is released. ePer says the full movement is ~10mm, but on my car (with no wear in the mechanism) it was about 18mm.

Mine was sticking. I had to remove and dismantle the turbo, as the vane was sticking due to rust on the cast iron interior, which I removed with emery paper. Since doing that 5 years ago, it's been fine. Before I bought the car it had stood for a year with swirl flap failure. The owner periodically started it but only warmed it up enough for condensation to form in the turbo, hence the rust. Sticking due to carbon desposits is also possible, and can be removed with oven cleaner. Search the forum for more info about that.
 

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Discussion Starter #28
Diagnostic show it is overboosting. 3 bar.
Already tried oven cleaner.
I poured the diesel additive yesterday,in fuel tank.
Vakuum pump is good idea,tnx.
 

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Diagnostic show it is overboosting. 3 bar.
Already tried oven cleaner.
I poured the diesel additive yesterday,in fuel tank.
Vakuum pump is good idea,tnx.
If testing with a vacuum pump shows sticky variable vane movement, you might have rust like I did. - pics here:
 

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Discussion Starter #30
Can you give me example of that caustic turbo cleaner ?
I want to clean without reassemble .
 

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Discussion Starter #32
Tomorrow I will try with ecu reset .
What you think about this ecu reset procedure?
 

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Alfa is different, battery negative off for 45min reconnect, turn key to mar wait 90sec turn key off for 90sec,start without pressing the pedal and idle for 15min,u will her the idling go up and down and will settle at the end switch off and wait 10min then start again and go for a drive
 
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