83 300sd power - PeachParts Mercedes-Benz Forum

tbopilot · #1 10-14-2008, 09:48 AM

I HAVE RECENTLY AQUIRED THIS BENZ. I HAVEN'T HAD A LOT OF EXPERIENCE WITH BENZ. WITH 300K MILES I'M SURE IT WILL HAVE SOME PROBLEMS. I DROVE IT TWO DAYS AGO AND IT DIDN'T SEEM TO HAVE THE POWER IT HAD WHEN I FIRST GOT IT. NOT KNOWING TO MUCH ABOUT THIS SPECIFIC CAR, I THOUGHT IT MIGHT BE THE TURBO UNIT. I REMOVED IT AND MADE SURE IT WASN'T LOCKED UP AND REINSTALLED IT. COULDN'T DRIVE IT THEN BECAUSE I HAD TO WORK.
DIDN'T SEEM TO SHIFT CORRECTLY EITHER. MY QUESTION IS...DOES THE VACUUM PUMP AND RELATED VALVES HAVE AN IMPACT ON PERFORMANCE? I.E. POWER OUTPUT.
THANKS
TBO

#2 10-14-2008, 11:00 AM

No. Why did you remove the turbo just to check it?

SD Blue · #3 10-14-2008, 11:12 AM

The vacuum system won't have an effect on performance of a diesel. Since diesels don't generate enough vacuum throughout the combustion cycle, they use an auxillary vacuum pump for accessories such as brakes, climate control, and transmission.

Start with fuel filters as they are the first likely culprit. When were they changed last and what was the condition of the removed unit?

Also, take a look at boost enrichment. MB uses air pressure from the intake manifold (look for a line going from the rear of the manifold and to a valve on the firewall) to the alda valve (look for a line going from the firewall valve to the IP) for added fuel when the turbo pressurizes. Many times these lines becomes cracked or plugged, or the flex fittings where it attaches, become brittle and crack. (BTW, this is a boost pressure line not a vacuum line.)