I have a 1987 300D with the OM603.

I have a reoccurring issue where while driving I will suddenly loose acceleration. The RPMs stay up and the engine revs but I get no gogo. Everything returns to normal instantly if I turn it off and restart, no need to wait or anything. Its normal in seconds or less.

I swapped the primary and the secondary fuel filters and it still remains the same. No excessive pressure or vacuum in the fuel tank. I am thinking it could be the solenoid connected to the he ALDA.

The EGR system has been deleted for years.

Thoughts?