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Unlikely Fuel Pump Issues

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skytow

Member
Motors are 2003 carbed 300HP Crusader small blocks... 462 hours.

So.... I went to start the boat after layup from the 11/12 winter. She coughed and sputtered and fired for a second on both motors then nothing... WTHeck?? I knew I was burning off some fogging oil so I used a small amount of ether and both ran for a few seconds and died... Hhhmmm.

So I check to see if I'm getting any fuel by checking for a squirt from the accelerators pumps... nope.. Weird. I also didn't hear the electric fuel pumps running and DID have oil pressure showing on both motors so they should be running!!

Now the weird part.... both fuses are blown on the electric fuel pumps!! Again, WTH? I put in TWO new fuses and they both blow. So I disconnect the fuel pump electrical leads at the pumps, put in new fuses, crank the motors until I get oil pressure, and they don't blow!

I'm having a hard time believing I have a double fuel pump failure on separate engines but have no other explanation. I now have TWO new pumps on order but just can't believe this is possible! (it sure is very unlikely)

What am I missing? Did ethanol / water kill these pumps (boat was running GREAT when I wrapped up in late November)? Is there some other explanation?

Stumped,

JD
 
Water will do the pumps in. Did you fog the fuel system properly when you put her to bed for the season? Did you try applying 12 volts directly to the pumps? Ran into this only once before, the owner had the fuel valves shut off, popped fump breakers. Ended up having to replace the pumps re running dry too long.
 
skytow said:
Motors are 2003 carbed 300HP Crusader small blocks... 462 hours.


Now the weird part.... both fuses are blown on the electric fuel pumps!! Again, WTH? I put in TWO new fuses and they both blow. So I disconnect the fuel pump electrical leads at the pumps, put in new fuses, crank the motors until I get oil pressure, and they don't blow!
Stumped,

JD
Click to expand...

The whole story isn't hear....so it is hard to point to a cause(s). Did you verify the OP switch is functioning? verify the connection from the starter solenoid to the fuel pump is intact? All the connections clean and tight?
 
The fuel valves were the first thing I checked and they were open. I did get voltage at the pump leads when the motors were cranked so I THINK I'm OK there but I will double check the connections between the starter solenoids and FP's as Mark suggests.

I did not apply 12V straight to the pumps although I was tempted. I'll try that once I have them out... (the stbd side is going to be FUN...) Too scary in the boat! I do have water separating fuel filters, one for each engine, that I replaced last fall. I had no evidence of water that I could find.

I'll report back when I get to the boat next time....

Thanks gents!

JD
 
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Remove the electric pumps they are locked with debris. You can rig up some jumper wires and a battery on your work bench out of the boat and reverse the power to the pump. Submerse the pump in sea foam while powering it backwards and the pump will start to run and clear it self. Let it run in the sea foam for a few minutes and then hook the power back up normal to run the pump in the other direction.

I do this to these pumps on a regular basis. If you keep installing fuses, with out doing what I described above, you will eventually burn out the pump.
 
All fuel pumps should be protected with a water separator and SCREENER (not filter) of 30 microns or so located before the pump. All carbs should be protected by a FILTER (not screener) of 10 microns after the fuel pump. Follow this guidelines and you'll be fine.

Jeff
 
OK, so here is the update I promised...

Long story short there was no visible debris in the first pump I took off (port side). In the process of removing it I went to loosen the metal fuel pipe that runs from the output side of the pump to the carb and I broke the fuel pipe as the brass fitting was corroded to the ferrous pipe. Bummer. Anyway, the pump came out and I disassembled it. As I said, it was CLEAN, no debris in the screen or anywhere else.

One of our marina mechanics happened along and I told him my story. He tells me he sees this all the time on the vane style pumps and blames it on ethanol which causes very slight corrosion between the vanes and the pump body when they sit for a long time. He had one customer with the same style pumps who only takes the boat out once or twice a summer and always has this problem. His suggestion was to put 12V directly to it with a jumper, momentarily, and it will almost always break loose. I did this on the starboard side and viola! She (the pump) ran like a champ. I put the recommended 5 amp fuse back in and everything was good to go.

On the port side I did install the new pump since I had everything out anyway and ran a temporary marine grade rubber fuel hose to the carb and now that side is running well too.

So, if you find yourself in the same situation, maybe you can learn from my expensive lesson! I'm just happy its all fixed and I can go fish!

On another front.... can anyone recommend where I can get those TINY little springs that sit under my Mallory ignition module in the distributor that help control the spark advance? I believe they are the return springs? I saw some rust on mine and want to replace before they break. I did not see them listed separately in the Crusader parts manual.

JD
 
Good tip!

for a mallory distributor, try their part number 29014. Make sure you know what you have before you change anything. If it a mallory distributor, write down the full part number and send an email to their techsupport crew. they should be able to get you a pair (or two) of the exact springs to give you the original timing curve. beware of wear on the pins and weights...if they aren't correct, the springs won't help much.
 
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