[Wheelstudpegcheck]

Fuel pumps run unles the battery is disconnected
Tank is pressurized until gas cap is removed
New pumps and filter replacement didnt fix issue
Wheres the accumulator on this model

 

[Noodles]

Is it a W213 E400 or a W124 400E ???

 

[Wheelstudpegcheck]

'92 w124 333k miles

 

[Noodles]

I love that model.
Going to move the thread to the W124 section.
There is an amazing amount of members and knowledge shared there.

 

[Floobydust]

Fuel pump relay (K27) fault (the contacts in the may be stuck closed)
ECU (N3/1) fault
Base Module (N16/1) fault.

 

[Wheelstudpegcheck]

Relay under rear seat? How would I test that
What's this ecu and base model stuff

 

[Floobydust]

Relay under rear seat? How would I test that
What's this ecu and base model stuff

Yes, I believe that on the V8 it is located under the seat. You could test for continuity on the contacts with an ohmmeter, but I believe the relay has some electronic circuitry in it, so just checking continuity may not be totally reliable. Replacement is the most reliable test. If you pull the relay, the pumps should stop running. If so, to me, the relay is the most likely cause.