SMP142

When I start the car, the vacuum pump starts to draw and closes my wastegate. After about 10-15 seconds at idle, the solenoid releases and my wastegate goes full open. This makes it to where I cannot produce any boost.

I swapped solenoids and that did not help. So... for the time being I have a line ran directly from my pump so it will be held closed.

It works, but it still does not boost really well due to the fact I think it is being de-fueled. No smoke at all, and bottom end is very sluggish.

Aside from getting the codes checked for a more precise reason, is there anything else that may be causing this issue?

***Car has the egr delete wired in which cleared by other codes.

junkyarddawg

The engine computer is not that simple on Mercedes, if it stores fault codes that effect exhaust emissions he will not close the wastegate until faults are corrected and codes are cleared. If you manually close the gate he still will not fuel the engine for boost. This is why you see guys are installing mechanical injection pumps on older 606 IFI diesel engines to eliminate the electronics, run bigger turbos and make more power. This is not so easy on common rail CDI engines and is also not emissions compliant. It may be possible to find a tuning shop that can retune the ecu for "off road use". I would probably just fix the faults related to current fault codes and restore the car to normal operation. This will also reduce the headaches and allow you to enjoy driving the car.