Fuel Pump maybe? Help me diagnose

[SRV220]

Hey all, I have '75 220. Motor is the 188hp mercruiser (Ford 302). Here's my story, maybe you guys can save me some time and money.

1st season with the boat - couldn't get it to run last year when I bought it - turned out to be quite a bit of water in the fuel. Early this season I had to dump the water/fuel separator a couple times to get out what I figured was the last of the water. Anyway, it's run great the last 4 or 5 times out, no need to dump filter, no problems at all. Little back story there, not entirely sure it's relevant, I'll let the experts decide that.

Today, I put it in the lake and started it up and it died a minute later. I dumped my fuel/water separator, and it started up and ran for a minute again. Dumped one more time, fired up and ran across the lake, ran great all the way. Pulled up to my buddy and it died. Ended up draining both batteries and never got it started again. Noticed that the separator never filled past half way and I was no longer seeing fuel spray in the carb.

When I got home a charged the batteries and put on a fresh separator filter and tried to run it on the hose. Never got any fuel into the filter and still no fuel in carb.

So, after my unnecessarily long-winded story, do you think my fuel pump is bad? (It was new late last summer. )

Am I correct in thinking that the separator is going to be full of gas at all times?

Thanks for helping a noob.


Missed out on a great day on the water, too!:smt009

 

[MorichesBayBum]

It sounds like you may have a clog on the pick-up in the fuel tank or you have a bad fuel pump. If its an electric fuel pump, make sure you have 12v with the ignition on. If its mechanical try filling the fuel filter with fresh fuel to prime it. Either way if you pull off the fuel line off of the carb, while cranking the engine you will see fuel coming out of the hose. I dont know what kind of carb you have, but there is normally a filter inside the carb where the fuel line goes into it. If it clogged, you wont be able to push fuel into the carb.

Good luck.

 

[SRV220]

Thanks, it is a mechanical fuel pump and the carb is the Rochester 2bbl. I'll check the filter on the carb, but...

Shouldn't the separator filter fill itself up if the fuel pump is good?

 

[SRV220]

Thanks for the help, turned out to be a clogged line. Wish I'd been smart enough to think of that on the lake, but I guess I'll know in the future. :smt101

 

[OldSkool]

In the future, if you suspect a bad fuel pump, use a one gal. fuel can and run a hose direct to the fuel pump. Make sure the can is remote away from the engine bay. Remove the line from the carb and run another hose from there back to the fuel can. Have some one turn the motor over and see if the pump is pumping.

An easy way to check the tank and fuel line is, while the line is off the pump, blow air back to the tank. You can usually do this without a compressor. Just blow into the line and listen for air bubbles in the tank. Much like blowing into a straw in a soft drink.

This may temporarily relieve the restriction and get you back to shore.