Sluggish 300SD

[glennet]

Recently I adjusted the valves and cleaned the
injectors on my 84SD. Valve clearance was rechecked after
initial adjustment and all clearances were set per manual.
Exhaust at the pipe is strong and even with much less smoke
evident upon initial startup.

My problem- The SD performs as normal until about the point
where the turbo should kick in and the car goes flat.
Very poor acceleration, and I'm not hearing the familiar
noise of the turbo kicking in.

I have pulled the airsupply to the turbo, turbo impeller turns freely with no axial or radial play - all fittings - vacuum and otherwise were returned to their original locations, and no obvious vacuum leak is present.

Can you offer some suggestions as to possible
solutions.

Thank You, Glenn

[mreid]

Try cleaning the fitting for the overboost switch where it come out of the intake manifold and make sure you are getting boost to the aneroid control on the fuel pump. Sound like you maybe bumped someting or broke a plastic line. They tend to get brittle with age.

I would try changing the fuel filter. It sounds like filter is allowing some fuel thru but at higher rpm's it's starving.

[h2odiesel]

Joe,

mreid is most likely right. your injection pump is not getting the boost signal. Here is a helpful link.

http://hsb.baylor.edu/html/easley/autofaqs/boostchk.htm