Technical 1.4 T-Jet Turbo Boost pressure

[edesl]

Dear All,
Since I bought my 150hp T-Jet 2 years ago, I always suspected it to be weak.
1 week ago I had the multiecuscan and while driving, the actual boost pressure vs. anticipated boost pressure was measured.
Seems my boost is low. Where the software anticipated 1bar overpressure, there the reality was only 0.5 bar.
My first assumption was to test somehow the waste gate control solenoid vac valve, but the multiecuscan did nost support to move it at the actuators page. Does anybody has idea how to make sure if the wastegate control valve is OK?
I mean this valve shown below.
BR
L

 

[Kusovi]

First check all pipes and clips.

T-jet 150 pulls really hard if everything is ok.

 

[Craig830]

O have been wondering the same for my 150, it pulls hard from 2000 to 3500rpm, then seems to go flat.

I will try and find out and post any info I can

 

[Craig830]

Is this helpful?

 

[Mgasp]

hi, try to block the output of diverter valve. it´s the pipe on the engine cover that goes back to air filter. have ride and try it. if it pull hard it´s the diverter valve that lose turbo pressure. I had the problem and found it that way. there was nothing wrong with MES, just no power. don´t drive like this for long or it blow the turbo, it´s just for testing, 1 mile or 2.

 

[edesl]

Mine is flat all across the entire RPM range.
The dash boost graphic display shows something, but that is surely not enough for glory.......

 

[edesl]

Thanks for advising, I will try to figure out something.
In Bravo case, contrary to the video, overpressure is used to actuate the waste gate.
So I need to check if the valve is letting through the overpressure in a standstill condition. Luckily no vac pump is needed, household air compressor will be fine. Vac pump is not so widely available as the air compressor. Nevertheless, in the video only the gage was used not the whole vac pump.

 

[aurick86]

you can use MES in Graph mode ... plot the boost pressure and the wastegate control solenoid %.. you will be able to see if the solenoid is having any impact on the boost.
These tests will need to be made while under actuall load.... car moving on road or dyno. at a stand still it won't build up pressure..


In MES you can actually use the wastegate actuator function to command the solenoid to open... you just need a piece of hose to blow through the solenoid (in the end coming from the turbo pressure port).

 

[Craig830]

Turns out my oil segregator is knackered. Lack of boost, high oil consumption. Air intake full of oil.

Only one flap is free to move even after hours spent cleaning, and then I fractured the diaphragm plastic plate.

Ordered a new one from shop4parts, hopefully it arrives soon!

 

[aurick86]

Well that could be a massive boost leak right there.

 

[edesl]

Turns out my oil segregator is knackered. Lack of boost, high oil consumption. Air intake full of oil.

Only one flap is free to move even after hours spent cleaning, and then I fractured the diaphragm plastic plate.

Ordered a new one from shop4parts, hopefully it arrives soon!

Hello Craig,
What component is it exactly? Do You have any visual explanation?

 

[Craig830]

Black box sat on the top of the engine.

It has nozzle that enters the rocker cover, a small diameter hose that connects to the inlet manifold, and a hose that goes to the air intake just before the turbo.

The hose to the air intake was full of oil, and if you disconnect it when the engine is running you can feel hear the boost leaking through as you drive

 

[Craig830]

https://www.fiatforum.com/grande-punto/352905-gp-t-jet-oil-consumption.html

Have a read through this, second page is useful

 

[Craig830]

I replaced my segregator today and it's like a new car!

Opened up the old one with a hacksaw at work to see what was causing the problem, hopefully the picture comes up well enough to show how much of a mess it was.

The smaller nozzle at the bottom of the pic has a valve in it that was permanently stuck open, allowing a lot of the compressed air straight through and back to the inlet.

 

[djyeo]

can you post a picture of where its located in the engine bay and if possible the link to a replacement part???

 

[newtjetuser]

O have been wondering the same for my 150, it pulls hard from 2000 to 3500rpm, then seems to go flat.

I will try and find out and post any info I can

Sorry to chat in this old threat, i have now similar but its have “flat” acceleration to 3000-3500rpm after that i feel its boosts more… Any suggestions?