Engine Not Running Properly

[(='_'=)]

last time i used my boat, the electric fuel pump was leaking, so i got one from autozone and replaced it. im not really sure bassboats use this same pumps, but the one that leaked said "universal fuel pump" and thats what i got, one of those you install externally on cars.

 

after that, i noticed the engine was not running properly. it would start quickly, but when i accelerated, it would gain speed for the first 10-15 seconds and then it would stop accelerating. it never stopped completely, but it did slow down considerably, and it didnt matter if i was going at WOT or barely faster than idle, the speed would be the same and it would have bursts of speed and then slow down again. i thought the filter was dirty and maybe the engine was not getting enough fuel, so i replaced it, and also cut a section of gas that seemed to have a small leak, i though the engine was getting air instead of gas. however, the problem continued. i had trouble starting it once, and when i opened the motor i noticed the carbs were leaking gas. after i let it sit for about 15 minutes, i started quickly again, but the problem persisted.

 

i also noticed the hand pump was not getting hard, it didnt matter how much i pumped it, it wouldnt get completely full.

 

from the fuel tank first i have the filter, then the hand pump, then the electric pump.

 

could it be the pump it sending TOO MUCH fuel?? or should i replace all the hoses to eliminate a possible air leak that could be letting air in the motor??

 

thanx!!

[Mr_Scrogg]

If the primer bulb isnt staying hard, you got a air leak.

[Fishing Rhino]

There are electric fuel pumps for engines with carburetors and fuel pumps for engines with fuel injection. 

 

You have carburetors.  Pumps for fuel injectors put out more pressure than those for engines with carburetors.

 

I doubt you should use a pump for fuel injection on an engine with carbs.  The pressure may be more than the needle and seat in the fuel chamber can handle, thus the leaking.

 

I didn't think you needed to "prime" fuel systems with electric pumps, at least not those with "fuel senders" mounted in the fuel tank.  In the tank, or out of the tank, the pump is activated when the ignition switch is in the "Run" position.  They will have a pressure relief valve which limits the fuel pressure.

 

Sometimes, it's less expensive to have an engine serviced by a competent tech, than it is to do it yourself if you are not sure of what you are doing.  You may be stuck with a fuel pump that will not work in your application.

 

I quit working on my vehicles several years ago when they became computerized.  Back in the day you could pull things apart and find a problem where some part was broken or worn out.  But without all the electronic testing equipment there is no way to determine if the problem is a bad sensor, and there are many on today's engines, or some other electronic component such as an engine control module.

 

Change plugs, change a water pump, replace fuel lines, or tackle any other relatively straight forward job, fine.  But beyond that, I'd leave it to the pros.

[Code54]

If you can, check the pressure and volume of the old pump and see if it is matching up to the new.  I would also look for an air leak - did you put a gasket in around the pump?  Also make sure all your lines are tight and nothing split when you reinstalled them.  Sometime the hoses will get a little split when you pull them off and won't reseal correctly.

[Way2slow]

First, the type motor would help, Make, horse power.

Second, I have serious doubts Autozone would have a pump in stock that would work. Unless you bought something like a Carter or Holly, high performance rotary pump that matches your application, you probably wasted your money.

As mentioned, the pump has to suitable for your application. You may have too much pressure and pushing the needles off the seats.

[tomustang]

First start with getting the right pump, then work from there

[(='_'=)]

well, the motor is an old 85 HP Johnson, from 1980 or so...

 

the old pump was leaking, it was sealed so i couldnt replace a gasket or anything. it was leaking bad, so i inspected it and saw it said UNIVERSAL FUEL PUMP, it was similar to this one:

 

 

so, i removed t and got another universal fuel pump, it looks like this one:

 

 

i didnt think about GPH at the time, i just installed what i had, it was sunday and autozone was the only store opened. the problem is i live 2 hours from my boat and i can only work on it saturday afternoon and sundays. therefore i have to do most of the work myself.

 

so, do you know which pump do i need?? is it a special pump that goes inside the motor? or maybe a smaller universal pump like those above?? i dont know the output f the old one, it didnt say anything except universal fuel pump, same as the new one....

 

so, assuming the pump is sending too much pressure or volume, shouldnt the primer bulb get hard and stay hard?? it doesnt, as much as i pump it, it will never get totally hard, and when i run the boat the primer bulb will get empty... to me that indicates air in the system... however, i cant see the leak, the hoses seem OK and there is no evident leak....

[sparky241]

Is it possible an airvent on the tank is plugged?

[Way2slow]

For that motor, you need approx 5 - 6 psi at a minimum of 30 gph. Most of those vibrator pumps will not deliver that volume. They also come in a numer of different pressure levels.

I also prefer electric pumps but I use the Carter 80 gph @7.5 or 15 psi rotary pumps and run those with a pressure regulator taking them to 6 psi. Now, this is also over kill for your application but it can be hard to find something between one too small and over kill. The Holley rotary is another popular model.

[Way2slow]

The motor has or had a diafram fuel pump. It probably went bad and it was cheaper for someone to install that electric instead of replacing the factory pump. You might want to make sure they are not pumping through the factory pump, that can cause problems.

Also, with an electric pump, I would remove the primer bulb, it's not needed and can be a restriction. The pump you bought should have a paper or on the box showing the pressure and flow rate. Anything over about seven psi may push the needles off their seats, and if the float level is set a little high, it can take less than that. That old of a motor may have been approx four psi, depending on the type fuel pump it had.