I may be dreaming, but I thought the main pump was not supposed to run with the key on, engine not running. The one in my 93 245 will run continuously with the key on. I don't think this was the case last week. What could be causing this, or should I pop open another and relax? Thanks.

I have a 1991 with the same system and the pumps run for about 2 seconds when I turn on the ignition, then they stop. My guess is that the main/fuel pump relay on yours isn't working right. It's supposed to determine that the engine is running and then keep the pumps running. It's a big white relay located near the ECU and EZ-116 control unit behind the passenger side kick panel. I'd try fiddling with or replacing that.

Thanks - I just replaced the relay as part of preventative maintenance. When I put in the old relay I get the same thing. It'll run on as long I leave the key on.

Mine cuts out after about 2 seconds. I assumed there must be a pressure valve somewhere that detects when pressure has built up and cuts the pump. Or is the pump itself pressure reactive?