Merc 140 runs for one minute then shuts down. Still fuel in bowl. (Solved)

[cheburashka]

My ongoing saga continues. I got paranoid about fuel in the bilge and decided to upgrade my '74 Mercruiser's "drain to bilge" pump to a newer-model pump with the hose that drains to the carb. Since then, nothing but problems.

I replaced the water separator cartridge and the in-carb fuel filter. I was having problems with too much fuel in the bowl overflowing and into the intake, so I installed a pressure limiter to make absolutely sure it didn't get too much fuel pressure. This stopped the overflowing problem, and now it idles very well. The problem is that when I throttle up, it goes fine for about a minute, then just dies. I've verified that theres still fuel in the bowl (enough for twenty or more squirts from the accelerator pump) and that it's not excess fuel coming through the vent and flooding the system. I have no idea what is making this happen. What can cause an engine to run fine, then shut down suddenly while there's still plenty of fuel in the bowl?

 

[cheburashka]

Re: Merc 140 runs for one minute then shuts down. Still fuel in bowl. (Solved)

Amazing what happens when you install the right parts. The fuel pump my parts supplier gave me was intended for a SBC. Apparently, it put out enough volume to overpower the needle and seat and flood the carb. I put on a new pump which was correctly matched to my engine setup and the problem went away first time out.