I installed a new areomotive fuel pump into the boat and I am unable to get enough fuel pressure. My pump is about 6 inches higher then the tank, this has to be as I have a belly tank.
This is how I have it plumbed in
I ran braided hose out of the tank through a 100 micron filter to an areomotive checkvalve that is mounted right to the pump, then to the fuel water seperator to the carb. This is per the instructions for the pump. I have also just ran it from the tank to the pump to the carb with the same results.
I have put a different electric on with the same results. What am I doing wrong?

Restriction on the pickup in the tank?? How much psi are you looking for?

Any chance the gauge is not accurate?

tried a different gauge no luck. Have checked the pickup on the tank w/ no luck.
I would like to see at least 6. I cannot even get 4lbs. I have thought of a way to get below the tank somewhat. I am going to try that tomorrow and see what happens.

Two things.
1) electric pumps do not like to pull. The pump is 6 inches higher than the tank, and that's not helping.

2) Be sure the vent line does not have an obstruction/ restriction.



Darrell.

How is the pump wired? You need to have a relay direct to the battery or your volt drop will not let the pump run full speed thus low pressure.

I run an aeromotive pump. It is not your problem unless you are running the SS pump for injection?

Suggestions:

1) run the seperator / filter then the pump, then an inline (~10 micron) filter then the regulator then the carb.

2) Check your fuel line fittings at the tank.

I had a tiny little tap at the outlet of my tank and a tiny 1/4" fitting. The rest of my system is 1/2" so it was't helping ( it was half shut too!)

Also, USCG mandates a one-way check valve for safety in your line that manufacturers put at the tank end. This is the most likely cause of your problem, disgard it. (don't worry, you have the areomotive valve in place anyway!)

My solution? All new lines from the tank to the motor, that way you know exactly what's what.


Good Luck!

Another thing to try is to pump fuel into a container.. be careful of fumes, sparks, etc. But watch for any air bubbles in the output line. That would indicate an air leak on the suction side.
Input line should be large.. larger than output. Any restriction on input will kill output.
Check voltage at pump, free flowing and under load.. as suggested above, a relay must be used. Is the ground wire tied directly to engine or battery..
Just some more thoughts. Keep looking.

Here is the way I ran mine. I removed the check valve on the tank, installed AN fittings and hoses from the tank to a pre-filter. Then from the filter to the pump, located slightly below the top of the tank. I have a belly tank also. Then to a high pressure high volume fuel filter water separator. I run 45 PSI for MPI so the better filter is needed. Some people do it with the water separator first then the pump then another filter. Good luck finding your problem.

Got it. I had the pump alittle to high. I was able to figure out a way to get the pump below the top of the tank. Running great pressure now. What a difference a few inches make.