2002 Rinker 212, Fuel Delivery Woes, Assistance Requested

jprovence

OK, first post here in regards to the engine.
5.7 Mercruiser, Ser# 0M321279, 2 barrel carb with electric low pressure pump:
Engine ran and started. Boat was winterized properly and ran at the mechanic prior to winterization. I started the boat and ran it after the winterization- started and ran fine on the muffs so I assumed ready to launch! Go to take it to the water, will not start. Not getting fuel. So, I go through and figure things should be done right. Rebuild the carb, new fuel pump, new fuel filter (Filled with fresh fuel before I put it on), new cap, rotor and plugs, new oil pressure switch and sensor, and new anti-siphon valve. I added a little stabil to lube the fuel pump before start to not burn it up. After this on the muffs, boat started right away has pressure, albeit a little higher than I like around 9-10psi. I run it, it starts and runs flawlessly. I start, let it get to temperature and then start/restart it a few times and its good. I then wait about 30-45min, go to start the boat and it wont start- no fuel pressure. I put 12v to the fuel pump and nothing. I have about 10v at the fuel pump wire if I bypass the oil pressure switch. I checked and have 0 resistance (ohms) between the purple wires coming out of the line to the pump as well as out of the fuel pressure switch. Engine has good ground from negative anywhere on the motor I have looked. I have another new pump as I ordered two of them. Plan on installing second pump and trying without the antisiphon valve today. The part number on the pump is the 18-8868/861155A3 pump which is the correct one for the motor.

Help! 

PickleRick

Anyting over 5 to 6 psi can easily over power the needle on your carb and fill you intake with gas. This can cause running issues and hard starting.  

It really needs a fuel pressure regulator to protect it if you are not running a proper pump for carb set up.

I've heard of a t being installed to allow excess fuel to go back to the tank, that psi may be ok if you have a fuel return. 

Sorry i cannot help you with the oil pressure switch, ive never worked with one.

If you've run a ground and 12v+ to your pump directly and she still doesn't work you have a bad pump.  Removing pump from boat and testing with small hose and clean fuel container on bench can rule out collaped/damaged/clogged fuel line/pick up.

Even with clogged or damaged fuel line she should still hum.

212rowboat

Where the fuel line attaches to the carb... get a towel under it.. get a wrench on the line... open it and close it quickly... you should get a little squirt of fuel. 

You're likely airlocked.. 

jprovence

Ok gents. After all this found the problem: line to the fuel pump had issues. I got it to start, and then jiggled the wire. Fuel pressure dropped. The harness that attaches to the fuel pump lines were spread out and not making good connections. She now runs great and was able to actually get her on the water today. 

I really appreciate the help and input. Will definitely look at a regulator. It seemed to run great today. No hard starts. Is the sign of overcoming the float fuel drips in the carb? How to tell if that’s happening?

thank you very much for the help.