2007 Tahoe 5.0 fuel issues

[jimmyc607]

I’m at a loss and just can’t seem to figure this thing out. Boat is a 2007 Tahoe Q6 with the Mercruiser 5.0 carbed motor. A couple weekends ago while coming back into the dock the boat just stalled. It would start back up but wouldn’t idle or stay running. Since then I have gotten the boat home and been trying to figure it out but haven’t had any luck. I have drained the tank and checked for water and all is good. I replaced the fuel filter/water separator and electric fuel pump. Also replaced the oil pressure/fuel pump switch but still same issue. The engine will start up pretty much every time but will not stay running and dies almost immediately. The fuel pump flows normally during cranking but it seems like once it “starts” fuel isn’t a spraying from the venturis. I tried hard wiring the pump to see if I could get fuel to spray in the carb, then pump comes on but still no fuel spraying out of the carb. Any advice is greatly appreciated.

 

[Scott Danforth]

What is your fuel pressure?

 

[nola mike]

I tried hard wiring the pump to see if I could get fuel to spray in the carb, then pump comes on but still no fuel spraying out of the carb. Any advice is greatly appreciated.

you shouldn't see fuel from the venturis at idle. assuming it won't stay running even with fp jumped?

 

[jimmyc607]

What is your fuel pressure?

Honestly not sure, there’s no fuel gauge but the pump and amount of fuel seems more than enough

 

[jimmyc607]

you shouldn't see fuel from the venturis at idle. assuming it won't stay running even with fp jumped?

It’s hard to tell because I’ve only been able to get the engine to idle for a few seconds by pumping and using starter fluid but I don’t really see any fuel spraying once running

 

[nola mike]

It’s hard to tell because I’ve only been able to get the engine to idle for a few seconds by pumping and using starter fluid but I don’t really see any fuel spraying once running

if the fuel pump is running, sounds like you need a carb rebuild

 

[jimmyc607]

if the fuel pump is running, sounds like you need a carb rebuild

I have a kit arriving tomorrow and and going to give it a try. I’m running short on time with my lake vacation starting next Saturday so at this point trying anything and everything

 

[Scott Danforth]

Honestly not sure, there’s no fuel gauge but the pump and amount of fuel seems more than enough

Get the inline test adapter and a fuel pressure gauge and test

 

[jimmyc607]

Get the inline test adapter and a fuel pressure gauge and test

I’m short on time, I have a lake vacation starting on Saturday. The fuel flow during cranking and initial start seem correct, but seems like once it starts there’s no fuel

 

[jimmyc607]

Would a bad ICM - ignition control module not allow the electric fuel pump to turn on?

 

[Scott Danforth]

Would a bad ICM - ignition control module not allow the electric fuel pump to turn on?

no