1996 3.0lx won't start after new fuel pump install

[Rugglesworth]

Hi everyone, I just replaced my fuel pump in my boat. 1995-96 3.0lx mercruiser as the old one was going out. Fuel in the yellow hose and other symptoms like missing at idle and wanting to stall at idle. It still was fine at cruising speeds.
After the install it fired right up and idled beautifully for a short while then died and won't start. I assumed that was what fuel was left in the carb before I began this repair. I pulled the fuel line attached to the carb and there was no fuel so thinking it was an air lock I cranked it until it started pumping fuel into a container. Buttoned it back up and it's just turning over again but no signs of firing up. What am I missing here? Again, it ran before this so it's definitely something to do with fuel.

Thanks in advance!

 

[alldodge]

Welcome
When you pump the throttle does fuel squirt down the carb?

 

[Rugglesworth]

Thanks! Glad to be here! I am doing this by myself at the moment but will grab one my kids to work the throttle and I'll see if I can see anything. One thing I didn't mention that I just remembered is I had been adjusting the air/fuel mix last time I was out to smooth out the idle before I realized the pump was on it's way out. I should seat the screw and turn it out 1 and a 1/4 turns as I believe right now it's mega rich? Maybe that has something to do with it?

 

[alldodge]

That would increase the idle mix but shouldn't cause that much of an issue.

Could be the carb needs rebuilding.

Carb was doing ok with lower then normal pressure from the pump. Install new pump and pressure is back up and the float needle seat is not able to keep the increased fuel shut off.

Just need more investigation

 

[Rugglesworth]

So there's no fuel squirting into the carb when the throttle is pumped... So what does that mean? Vapor lock of some sort? Can I remove the fuel line and gently blow through there to see if there's flow? I'm mechanically inclined but not a carb guy unfortunately. yet....

 

[alldodge]

Making me scratch my head, the LX doesn't use a pump rod so what was the part number of the one you used.

https://www.mercruiserparts.com/bam/subassembly/30920/2330/60

 

[Rugglesworth]

Yeah really weird. I just kept playing with it and finally fuel started coming through the jets..... now its running again. Weirdest thing. Thanks for your help