86 300sdl, slow acceleration - PeachParts Mercedes-Benz Forum

NeilC · #1 06-07-2002, 02:53 PM

Car takes about 20 seconds to get to 60mph. How do check if the turbo is working and system to controll is working? Anything else I should check?

sixto · #2 06-07-2002, 07:34 PM

Clean the line from the intake manifold to the ALDA on top of the injection pump.

Temporarily bypass the overboost switch. Sometimes the boost sensor sticks.

Check that the air recirculation thing under the EGR valve isn't stuck open. A quick check is to plug the line to the recirculation valve. That doesn't help if the valve is physically stuck open, though.

Sixto
91 300SE
87 300SDL

NeilC · #3 06-07-2002, 08:23 PM

Alda? If I do all this, does this mean the Turbo is in need of replacing? Can they be rebuilt?

sixto · #4 06-08-2002, 02:28 AM

Simply giving these Diesels more air does not increase power output. The ALDA is the anaeroid (sp?) compensator that instructs the injection pump to provide more fuel under boost.

One thing I forgot to mention was to hook up a boost gauge to one of the nipples on the intake manifold. If you see boost, then the problem is not with the turbo. You'll have to test this with a load on the engine such as while driving the car. Reving the engine in neutral will not create boost.

I believe the turbo can be rebuilt and obviously it can be replaced.

Sixto
91 300SE
87 300SDL