Xantia Activa Overboost problem?

[bLuLine]

Hello

Well im going to try to explain this the best way i can since english is not my main language.

I have a Xantia Activa 2.0 Turbo and for about 2 years the car when goes past 4k rpm on higher gears (3rd and up) then engine cuts fuel and a yellow light appers at the dash.
In these 2 years ive been replacing parts that potencially could cause this issue, i changed the ignicion coil, spark plug leads, spark plugs, the "elctrovalve" (i think the normal name is the factory boost controller) checked every pipe if i had any leak and checked the intercooler also and more and more. I literally changed almost everything except the turbo itself and its components (wastegate for example).

In the last weeks i installed a blow off valve (hks super sqv) and a boost gauge and ive been taking some notes on the pressure.
The car comes to boost very quickly 1.5 rpm 0.5bar and goes to 3k screaming at 1.2bar until it cuts fuel at 4k rpm at 1.4bar!!! (thats 20psi )
I will post an video here later this week showing the boost gauge at those pressures.

Now i am very worried about this pressure levels, or i installed the boost gauge incorrectly and its giving inaccurate readings (don't really think so this is the case) or im having a serious overboost problem and that explains why the engine cuts fuel at 4k rpm. (i researched a little and learned that this car has a 1bar limiter)

So finally my question here is:
Does anyone know what my problem could be and what's causing it?

My final suspicion is the wastegate actuator is damaged and does not work or is working incorrectly.

Sorry if i have any errors and please if you have any ideas just say.

Thank you

[Hell Razor5543]

I believe (but I am NOT certain) that the ECU expects the turbo to run at 1bar (14.7PSI), and that when it goes past that it drops into limp mode. It is not a high pressure turbo, but it covers a greater rev range.

I am sure that somebody with a lot more Activa experience (over to you, CitroJim) will come along with a lot more useful information.

Oh, and welcome to the forum.

[bLuLine]

Many thanks, ok i hope he will notice this post

[CitroJim]

Many thanks, ok i hope he will notice this post

I have now, after James pointed me to it!!!

James, you are right about the ECU and boost levels...

If you are running the standard boost regulator and NOT an after-market manual boost controller then your problem is very likely to be the wastegate vacuum pipe has a hole in it... This will result in no control of boost pressure and the symptom you are experiencing.

The hole (or more likely a slit or crack) will most likely be found at the wastegate end of the pipe. It is not easy to see or check.

Hope that fixes it for you

[bLuLine]

I will try to check that on the weekend Jim

Another question btw what's the worse it can happen if i leave it like this?
And another question: is the 1.4 bar pressure going to engine or it counts with the "leak" ?

And many thanks Jim

[CitroJim]

The worst that can happen is the engine is in limp mode and runs poorly. No damage will result...

In limp mode the engine is protected as it is incapable of generating a dangerous amount of boost...

Have you confirmed this is definitely the problem with a Lexia diagnosis session?

[bLuLine]

Last time i ran lexia ( i don't own a software yet and don't know how to get one and use it ) it showed an error of incorrect or extra air in the system i don't know if this is correct sadly i don't remember it exactly... but lambda sensor is new i replaced it, this could be a leak in the turbo system like you said correct?

[CitroJim]

That does sound correct, yes. I can't remember the exact wording of the error that comes up on a Lexia now...

I know someone who does who should be visiting soon... I'll ask...

[bLuLine]

Ok Jim thank you.

I will try to check the wastegate vacuum pipe on Saturday i will update here the results.

And maybe i will check if i can buy the lexia 3, do you recommend any seller by any chance or do i just check ebay?

[CitroJim]

No, it was many years ago now I bought my Lexia 3 from ebay. Hopefully a more recent purchaser can advise...

[Hell Razor5543]

I got my Lexia kit from Easy Diagnostics. It is not the cheapest, but they seem to know what they are doing, and will help out as much as they can. I don't know what the postage would be to Portugal, but if you mention that you are a member of this forum they might (only might, I am not sure they will) not charge for the postage. You will need to have a computer that is running a 32bit version of Windows, as, while Diagbox can handle 64bit systems, Lexia is so old it is 16bit, which can be addressed by a 32bit Windows, but not directly from a 64bit Windows (you will have to use a Virtual Machine configuration).

http://www.easydiagnostics.co.uk/" onclick="window.open(this.href);return false;

[bLuLine]

Ok thanks for the link James i will check it.

Running it wont be a problem i have an old IBM laptop with winxp 32b

[Hell Razor5543]

How much memory does the laptop have, and how much can it be upgraded to? The Lexia system needs a lot of memory (at least 1GB for it to work well).

[bLuLine]

I think but not sure i have 2gb in it, my father upgraded it because it was his working laptop.

[Hell Razor5543]

So long as that is memory (RAM) and not storage it should be fine, regardless of where you get the Lexia kit from. One thing to check is which version of Diagbox it comes with. Some Chinese clone chipsets have been blacklisted, and the Diagbox software can recognise these. As a result these units will only work with Diagbox up to version 5.29. Later chipsets don't have this problem.