302 problems, dies under a load

[daniel240]

I just replaced my 302 in my 1975 trisonic. I also replaced the distributor cap, rotor, plug wires, fuel pump, and fuel filter/water seperator, and rebuilt the carb. I got the motor running at the house and it revs fine and sounds good in nuetral. When i put the boat in the water and put it in gear it will idle but if i give it some gas it will sputter and die around 1000 rpm. I dont think im getting fuel to the carb. I pulled the line going to the carb and cranked the engine over and I am getting very little to no fuel out the line. I dont know what else could be the problem. My boat has 2 aluminum fuel tanks on either side with fuel lines connecting at a T. From there the fuel line goes to the filter/water seperator, then to the fuel pump. Im stuck, please help!

 

[a70eliminator]

Re: 302 problems, dies under a load

Your mechanical fuel pump should discharge some pretty healthy pulses of fuel with the outlet hose off, it should easily fill a coffee mug with just a few revolutions of the motor.

 

[Maclin]

Re: 302 problems, dies under a load

The fuel pump lever rides against an eccentric add-on lobe on the cam. If the eccentric is flat or not swedged on/slipping then no pump action. You can test the pump's action on a bench, just have to put a lot of weight into it to move the lever and hold a finger over one of the in or out fittings.
If it acts like it should pump then whatever the lever is supposed to be riding on either is not there or something is wrong with it.

 

[Bondo]

Re: 302 problems, dies under a load

Ayuh,...

Have you Checked from the Tanks to the fuelpump,.... Are the lines Clear,..??

 

[daniel240]

Re: 302 problems, dies under a load

tomorrow I will disconnect the line from the fuel pump and put it in a small gas can and see if that pumps fuel out the line. if that works then I will know that the problem is before the fuel pump. I was also wondering about the lobe that you are talking about that the fuel pump arm rides on. But this was a new rebuilt motor that came assembled so i would thing they should be ok. From what I remember those lobes are not adjustable.

 

[Maclin]

Re: 302 problems, dies under a load

Do the separate fuel can first like Bondo said, that will shed a lot of light on what is going on.

The lobe that runs the fuel pump lever is a separate component that goes on the end of the camshaft behind the timing gear, much bigger radius than the lifter lobes.

If the fuel pump was installed by the builders then all should be ok, but I wanted to get the fact out there that there can be other reasons that a good fuel pump won't pump.

 

[daniel240]

Re: 302 problems, dies under a load

the fuel pump was not installed by the engine builders, I installed it myself. I do remember seeing the lobe you are refering to. If I remember correctly it looked like a round peice with a hole that was off center that bolted it to the camshaft, maybe around 2'' dia.

 

[daniel240]

Re: 302 problems, dies under a load

Today I removed the fuel pump, left the hoses connected, and manually pumped the arm by hand and I was able to get a lot of fuel to pump out of the line that goes to the carb. After I did this, I bolted the pump back in and cranked the engine over and no fuel came out of the line. So I guess this tells me it has to be that lobe inside the engine that the fuel pump arm rides on. Why would this not be working properly? Like I said I bought the engine fully rebuilt block and heads assembled. Is this something that I should have swapped over from the old engine? I really dont want to have to take the front of the engine apart but I guess thats what I will be doing.

 

[Maclin]

Re: 302 problems, dies under a load

There may be some Ford guys watching this and may show up with a tip on how to check the eccentric without taking the timing cover off.

Maybe "modern" 302's do not have eccentrics on the cam for mechanical fuel pumps, expecting that the engine will be fed with an electric pump. It may be that an eccentric can be added if it was not installed, or could be that the cam was "modern" and did not allow for an eccentric, to me that would be odd. The spacing behind the timing gear may be an issue if the cam is not designed for an eccentric. Some of this is conjecture, hopefully the Ford guys can fill in some blanks for you.

I would call the builder right away and ask some of those questions, they may be able to shed some light.

Good luck, hopefully it is a simple thing.