454 Mercruiser stalling issue - help!

[Glen S]

Hi all
Have a 1991 350 Sundancer with 454 Mercruisers (carbureted). Both start and run fine. But when we shut down for an hour or so after running, the port engine will stat fine but after a couple minutes of idle will stall and not restart. Got it to do this at the dock today after a run and was able to see that there is basically no fuel at the carb. There is a tiny amount in the accelerator pump but that's it. If I pour some fuel in the carb it will briefly start. I swapped coils to confirm it was not a spark issue. Have replaced the fuel filter and serviced the water separator (new element and seals). I disconnected the fuel line to the fuel filter from the tank (via water separator and port/starboard tank valve). There was no fuel in the line. Have disconnected the line at the tank and can suck fuel out of the tank OK with vacuum pump.
Have a new fuel pump I was going to install this week. Was wondering if it is possible a fuel line is deteriorating and collapsing? Have also checked the inline filter at the carb. Seems to be a heat soak effect. Any suggestions or insight would be much appreciated?
Thank you

 

[northern]

With the mechanical fuel pump there is a cam (Round rod about 1/2" dia) that makes it work. You can feel it after you take out the old one. It will have fallen down so the pump cam will not go in. If you lift up the cam and pack the area with wheel bearing grease it will hold the cam up and the pump will go in without effort. I tried the wire trick to try to lift the cam up but it did not work. I have changed one 3 times. OEM (Last one I put in) fuel pumps are worth the extra cost the cheep ones lasted a hundred so hours.

 

[Glen S]

With the mechanical fuel pump there is a cam (Round rod about 1/2" dia) that makes it work. You can feel it after you take out the old one. It will have fallen down so the pump cam will not go in. If you lift up the cam and pack the area with wheel bearing grease it will hold the cam up and the pump will go in without effort. I tried the wire trick to try to lift the cam up but it did not work. I have changed one 3 times. OEM (Last one I put in) fuel pumps are worth the extra cost the cheep ones lasted a hundred so hours.

Thanks for the advice. It is an OEM fuel pump.

 

[hpcrank]

Hi all
Have a 1991 350 Sundancer with 454 Mercruisers (carbureted). Both start and run fine. But when we shut down for an hour or so after running, the port engine will stat fine but after a couple minutes of idle will stall and not restart. Got it to do this at the dock today after a run and was able to see that there is basically no fuel at the carb. There is a tiny amount in the accelerator pump but that's it. If I pour some fuel in the carb it will briefly start. I swapped coils to confirm it was not a spark issue. Have replaced the fuel filter and serviced the water separator (new element and seals). I disconnected the fuel line to the fuel filter from the tank (via water separator and port/starboard tank valve). There was no fuel in the line. Have disconnected the line at the tank and can suck fuel out of the tank OK with vacuum pump.
Have a new fuel pump I was going to install this week. Was wondering if it is possible a fuel line is deteriorating and collapsing? Have also checked the inline filter at the carb. Seems to be a heat soak effect. Any suggestions or insight would be much appreciated?
Thank you

Northern is correct about the grease. This trick works even better if you put the rod and the grease in the freezer for an hour or so before install. Use the garage beer frig's freezer, not the one in the house!

hpcrank