Too much boost???

[keithcdi220a]

[FONT=&quot]Well I have had The turbo refurbished.
The EGR cleaned.

Took the car on the road with diagnostic connected, goes like a rocket on pull away then drops in to limp mode.

Below are the Diagnostic readings when stationary.

Intake Air Pressure 996 [800.... 1000]
Boost Pressure 1001 [1043....1093]
Charge Pressure Positioner 95 <=90 This goes off the clock when
accelerating.
Boost Temp air temperature.47.5 <=40
Atmospheric Pressure 980 [800....1000]

[/FONT]

 

[keithcdi220a]

Well judging by the lack of replies no one has the knowledge on this problem. So it looks like an expensive visit to Mercedes.

 

[Black Scorpion]

Sounds like it is over boosting.
It is getting too much boost pressure and this in turn tells the ecu there is a fault and hence the limp mode.
When the turbo was taken apart for the refurb work the actuator has been removed and put back but not adjusted.
Adjust the actuator to the correct amount of pressure and the car should run fine.
Hope this sorts your problem.

 

[keithcdi220a]

Hi black Scorpion thanks for the reply.
It had a new actuator fitted the refurb was done by a specialist turbo company Cats& Carbs. They say it was all matched up.

 

[Black Scorpion]

Ok if they say it is all correct then look at the over boost switch.
Not sure where it is on your car but will be in or around the boost pipes.
Check it has been connected after the work.
If it is connected then it could just need a good clean with carb cleaning fluid.

 

[keithcdi220a]

Hi Black Scorpion.
Had it on a star diagnostic, found the boost flow hose off.
When I took it back to my local garage who is fixing the car he said it kept blowing the pipe off. I pointed out that the securing bolts were missing from the attachment plate. Back to the garage on Monday as he assures me it will be fixed fingers crossed.

 

[Black Scorpion]

Glad it is nearly sorted.
You can now enjoy the car without worrying about any problems.