Get rid of a crappy mechanic that sets the timing wrong! That might just be the problem as just being off 3 or 4 degrees on timing can make a big difference. Its easy to check with drip tube.
Bypass the valve thing for a test by running a rubber line directly to the ALDA from the intake manifold banjobolt. If you need one I can supply the right one with pipe nipples. cheap.

Injectors are next, if plugged by dirty WVO stuff then its obvious what you need in the way of fuel delivery and I hope the IP isn't involved.
Drive that thing over the hill to the Bay Area and find a decent shop. I know several. Please don't ask me to help I am up to my eyeballs with job and travel.

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'95 E320 Wagon my favorite road car. '99 E300D wolf in sheeps body, '87 300D Sportline suspension, '79 300TD w/ 617.952 engine at 367,750 and counting!