240 efi fuel press. question

[teammullet]

So I'm checking press @ Schrader valve whe n key switched on, 46 psi for about 4 sec. Is that lift pump press. Or high press pump press.does lift pump only run until pulse pump takes over or does it keep running?46 was eng. Off but is that to high?I thought the high press pump would run aanytime the key is on?thanks in advance for your help

 

[Dr Honda]

Welcome... and these guys won't know. That's a Merc engine... so I'll move this thread for you.


But to answer the question...

The lift pump is low pressure, and just feeds while cranking. Once the engine starts... the pulse pump continues to feed the vapor tank.

The high pressure pump runs whenever the key is on. Depending on the ECU... it will turn off if the engine isn't running. So... check the pressure running.

Oh... and tell us the year of the boat, and/or post the serial number of the engine. (There were some changes over the years)

 

[teammullet]

re

Welcome... and these guys won't know. That's a Merc engine... so I'll move this thread for you.


But to answer the question...

The lift pump is low pressure, and just feeds while cranking. Once the engine starts... the pulse pump continues to feed the vapor tank.

The high pressure pump runs whenever the key is on. Depending on the ECU... it will turn off if the engine isn't running. So... check the pressure running.

Oh... and tell us the year of the boat, and/or post the serial number of the engine. (There were some changes over the years)

OK thanks. Boat is a 2003 challenger 2000 eng tag says 2002 240 efi 0e411980 am I correct that its a gen 2. What is the differences between gen one and gen 2? Is there any diagnostic scanners other than the Marc DDT? Those are crazy expensive,would the smartcraft gauges show faults with sensors?

 

[Dr Honda]

Yep... it's a gen 2 engine.

The core engine is really the same... but everything bolted to it changed. (oil pump, entire EFI system, ECU, and so-on)

Yes... there's a few things you can do. Rinda makes a great scanner for the Mercury engines... but your engine is full "Smartcraft" compatible. So, the digital mercury gauges can show error codes.