Hi,

I have a 2005/12 Focus 1.6TDCI 109HP

I have for some time had several issues with the car, but for long time i get over boost failure.

I have a readout of boost up to 2.5bar where the sensor reaches the maximum.

I have checked the variable flaps are runining smooth.

there is vacum on.

It regualates, but when i get high boost i can see in the ECU it regulates the Boost controller down to 18% approx, but the boost is still high.

Today i took the power off the boost controller, and drove, up to 2000rpm it was at 100KPA, but afterwards it came up to 130KPA at 3-3500 RPM.

Is this a leaking boost controller? or a Bad Turbo, it seems the flaps goes entire back...

Or is that normal when the output from the motor increases?

After the problem came, i have taken out the DPF, with no remap, but the problem exists but before and after.

I have also been drivning with EGR blanking plate and without with same issue.

The turbo i am driving now is a loose cartridige from china, before that i had a geniue GT1544, and before that the original.

I do not know if the 2 others produced overboost.

So for know i could think it is the turbo there is not running correct, or the boost controller, or the ECU not going lower than 18%???, or maybe the vacum pump there is making too high vacum?

http://rapzak.dsmynas.com/boost.png

Thank you for your advice.

Kasper

130kpa is about 19psi - thats ok / not too high on a tdci

the boost controller controls the boost pressure level - not the turbo, you can change the turbo and the peak boost pressure should remain the same

if there is a leak in the boost controller it "thinks" there is not enough boost, so the boost rises, and rises

have you had the fault codes read?

you should fit a boost gauge, to keep an eye on it

Hi,

The 130Kpa is when there is no power to the boost controller (Valvle) so the vanes must be in most "off" position.

I have peaks up to or over 2.5bar.. look at my link.

I get an overpressure failure code in ECU

According to this link:

http://uk-mkivs.net/topic/34834-vnt-tdi-turbo-how-to-adjust-actuator-cure-boost-problems/

It can be a wrong rod distance... i have a exchanged cartridge...

Kasper

What im saying is the cartridge, compressor or turbine does not control the boost pressure level, changing it will not cure exessive boost

Qoute:

if the VNT rod is too short then it will effectively make the turbo far too sensitive and as soon as the ECU requests boost, before you know it you have twice the amount of boost requested as it suddenly spikes. once it does this, it's basically lost control of the boost and for some reason it won't go into limp mode, instead you will just feel a flat spot and if you have a boost gauge you will notice it going off the scale! the reason for the flat spot is the amount of EMP (exhaust manifold pressure) suddenly generated is too much to get though the turbine, so the engine is choked and held back. once the boost falls to a reasonable level you will feel the car start to pull again.

This is what i mean...

I am aware it is a closed loop regulation, but it can make overshoot/undershoot....

Kasper

Btw... My data is availible here:

http://rapzak.dsmynas.com/ford/

Do not take to many samples, it will take ages...

Kasper