Overboost relay can be full of ****, mine was and made my car a slug. Then my cat was also plugged, gutted that and the car runs fantastic.

I would purchase a simple vacuum/boost gauge so you can do your own testing. You need vacuum to set the trans system on it and boost, to you know... see how much you are getting. It could easily be making proper boost... or not. Spec is about 13psi. A bad turbo (think seized) would make NO boost and the car would barely be able to run due to the exhaust restriction.

I second inspecting the throttle linkages, the ones by the firewall have a small nut. 10mm? That likes to become loose over the years causing lack of travel to the IP making the vehicle slow. I had this on my SDL and SD, both would necessitate a running start to merge into city traffic when I purchased.

Hell, you could have a bad ALDA preventing fuel enrichment.

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I'm not a doctor, but I'll have a look.

'85 300SD 245k
'87 300SDL 251k
'90 300SEL 326k

Six others from BMW, GM, and Ford.

Liberty will not descend to a people; a people must raise themselves to liberty.[/IMG]