Hi
i’ m french and i have a 997 turbo mk1….
but i have a problem… i loss boost between 4000 and 5000 rpm… 10-11 psi…
New map sensor, new maf, new injector, new spark and plug, new exhaust with 200 cat, big wagner,new gas regulator, new o2 sensor, boost test = no leak….

 

My log

 

Were all of the new things done to try and cure your pressure drop, or were these done just before you noticed you had a boost problem?

Ed

 

yes everything has been changed to overcome this problem… vtg rods, diverter valve , knock sensor and valve solenoid also change

 

Holy cow... in all of this has anyone done a smoke test to check for a vac leak?

Ed

 

Are you able to log all ecu parameters? Unsure how unrealistic that is or how slow the data rate would be. Not really familiar with Porsche ECUs.

Even better, is there a list of what you can log and send that to me? Then we can pick out what to log, have you do another run and you can send me the CSV?

I have the MegaLogViewer HD software so I can look at logged data and see if anything stands out.

 

What about a compression and leakdown test?

 

Try replacing the rubber boot that connects the y-pipe to the throttle. That's often reported as an intermittent source of boost leaks. But agree, a boost test (at 20psi /1.5 bar) should find that.

 

Looks like a Durametric log? Remove the cylinder misfire values, remove the lambda set points, ie strip it down. 4 samples a second blows.. pun intended. You most likely have a leak (as guys have reported)
Pressure test the system to 15PSI to start with. Forget the Smoke testing..
Then tick RPM, Actual Boost, Throttle, Lamda Actual both banks. Hopefully you can get 15 to 20 samples a second. You might need to run a battery pack to your laptop to get the processor to max out.