I have gone through a long process of trying to determine the cause of the low power problem with my '87 300D. The problem occured gradually over 2 month period. The car is very slow off the line and struggles to reach 3500 RPM where it just runs out of steam.

I had the throttle linkage replaced last summer and had the shop check for full travel when I started having the problem. Getting full travel they say.

The car idles well and doesn't smoke. All filters are new. Fuel in prefilter is clean. All pressure lines are new and clean. EGR and ARV are disabled.

When I checked boost pressure between manifold port and ALDA I was only getting 3-4 PSI.

The ALDA was not holding pressure, so replaced shaft seal and it now holds 15 psi with very slow leak down. No improvement in performance.

Discovered a few loose intake manifol bolts. Replaced intake manifold gasket and torqued bolts. Replaced air pipe gasket and O rings.

Exhaust sounds normal, not restricted.

In looking at the turbo, the shaft seemed somewhat hard to turn. Sent turbo out for rebuilding. Tech said that waste gate flap had come loose from rod in turbo so it was open all the time. After rebuild, turbo tested to 14.5 PSI before waste gate started to open.

Got everything back togeather this morning and went for a test drive. Very little improvement if any in performance. This is becoming a bit depressing. Makes we want to buy my '83 300D back from my daughter.

Am I looking at a fuel delivery problem or possibly a computer/electrical problem?

Any and all suggestions will greatly appreciated.

Thanks
ewstan