[Guest]

Today, while driving on the interstate, I noticed my car would boost to 10psi until about 4500 rpm. When the 2nd turbo was coming online the boost pressure would drop to 6-8psi.
The car idles and runs smoothly. Pressure drops at about 4500rpm. I was running 18psi.

Any ideas.

Thanks
-Steve

 

[dzeiler]

go to the mkiv.com site got to the tech page do the temp TTC if you fix the problem then that narrowit down to the sequential operation and a blown vsv or actutator. It is unlilky a leak in the IC becuasue you are getting normal boost in #1 if the problem persists in TTC that makes it more likly you blew #2.

 

[pooshda]

Thats EXACTLY what my car was doing... er... IS doing..

Another thing... Dzeiler... when I 'apparently' put my car in TTC mode it still made boost at 2200rpms at the same time Turbo 1 always made boost.. isnt it supposed to be more like 3000rpm?... because If thats the case then its possible the generic checkvalves I used didnt work correctly and I should try TTC again or ETTC shouldnt I?... or is it supposed to make boost at 2200 still.. I swear it said the lag increased and it made boost at about 3k instead in TTC... correct or not?

Im hoping that maybe its not really in TTC for some reason and that I can still find out #2 is alive and well

 

[dzeiler]

in TTc you should not make boost till 3000 or so. pooshda i would check your egcv actuator the diaphram is prbably shot look at mohad pvt page on mkiv.com he ahs some pics of the blown diaphram if the diaphram is bad pressurizing it to go TTC won't work. The egcv is the actuator at the bottem of the engine on the passenger side follow the vacuum hose from the wg vsv back to it you put a check valve on that line. You can hard wire the actuator closed if that fixes the problem just replace the actutator and your back in business.

 

[pooshda]

I have no idea where that page is... closest thing I could find was Mohd A's page in the readers rides section.. but there was no info there that i could see... I checked tech articles section too, didnt know where else to look... mkiv.com needs a search function but it would most likely not work anyway..

Anyhow thanks again.. Ill see what I can find after work.. im sorta blind when it comes to all these actuators and what not... but im getting a little better everyday by messing with this car

 

[Guest]

Strange?!?!

Thanks for the replys.

After I posted this last night, I took the car to the shop and it was running fine. It seems to run very well until it heats up.

I have a pulled wastegate hose. I am boosting roughly 14psi in 1st&2nd, 16psi in 3rd. I was boosting 18psi in 2nd, and it would climb up to 20psi in 5th.

I'm going to check MKIV.com.

thanks again
-Steve