Currently operating on a '94 Ram that really just seems to run only when it feels like it.I have checked the fuel pressure (5.2 port inject)and when it did actually decide to run the PSI was between 45-54.I assume that is within specs while the engine is running.Now from the reading I would assume the fuel pump was O.K.,at least the pumping mechanism,maybe not so much the electrical side of the fuel pump.

The problem is that sometimes there is no fuel pressure at all...turn the key on 30 times and the fuel pump might engage only 2 times.

There are four wires running into the fuel pump module on top,I assume that 2 of these wires are hot wires (1 for sending unit/1 for pump itself)and the other two are grounds right ?
I have the Haynes manual for the truck but the wiring diagrams are too generic to really follow and color codes in the book do not match what I have on the truck.

What I would like to do is bypass all factory wiring and run 12v straight into the pump itself which I am guessing to be the largest red wire that runs into the top.While using a test light I did not have power through this wire,only the one I assume to be the sending unit power supply.The other 2 wires (that I assumed to be grounds or 1 running up to the fuel gauge)also did not have power.

I know this is not a relay issue and have swapped some around to be sure.Has anyone experienced this same issue and is it as obvious as a bad fuel pump like it would seem?

This is not my truck and the owners viewpoint is that a fuel pump cannot be bad one day then work fine the next....Any good ideals before we go through the hassle of dropping the tank ?