I have an 83 300D-turbo, when driving up an incline (hill) at freeway speeds I experience a major loss of power, down to speeds of 35-40mph. replaced the fuel filter and added fuel additives (bg k44) had the valves adjusted and vacuum valve replaced, as well as the waste gate hose. This did not help. This loss of power only happens at freeway speeds not in town. Wondering if it could be worn fuel injector or pump? Any ideas? Maybe bad fuel lines? Any help would be great.
Thanks.

does your primer pump leak when you pump it...if so replace it. Clean the banjo bolt again.

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when i changed the fuel filter, i did not notice any leakage from the primer pump. I'm thinking its not getting fuel at times due to the hill or incline on the road that I'm driving on. Had the altitude compensator cleaned and hoses checked for leakage found nothing. Any other ideas?

how do i find and clean the bajo bolt

Mine doesn't want to pull a hill either- I'm boosting @ 8 psi, check your boost pressure. Needs to be around 12 psi. Only other thing I could think of to do would be clean the tank screen out. Check your accelerator linkage too to be sure you're getting the full travel of the mechanism.
You need to check and see if your turbo is boosting at all, then check the boost pressure. If it's not 12 psi at wide open throttle @4000 rpm, you need to adjust the wastegate spring. I think you might be in luck there as '83s might have the KKK turbo which has the adjustment screw outside the housing facing the passenger side fenderwell. I have the Garrett which is a pain in the ass to adjust.
If you are not boosting at all, check your switchover valve at firewall, and also the boost pressure sensor mounted on top of the intake manifold. Either or both could be bad, as in my case. I now feel the turbo whoosh at the intended rpm for my model, it just peters out at 8 psi.
Banjo bolt is the hollow bolt mounted directly to the rear of the intake manifold, and it has a plastic tube attached to it. This tube should run to a valve mounted to the firewall, then to the ALDA or aneroid compensator(you called it the altitude comp). Sometimes this bolt gets crudded up and the boost signal never makes it to the injection pump.

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