Electric Fuel Pump

My M715 had an electric pump installed when I got it three years ago. The fire department did a very good job of messing up everything they touched. A clothes pin held the rubber inlet hose to the stock fuel pump metal inlet line. They just bolted the inline pump to the old fuel pump/vacuum pump housing. I installed an Auto Meter fuel psi gauge in the dash, with the sender between the fuel pump and the carb. I have never had more than 6 psi at anytime at the gauge. For the last week or so, when I drive the truck home, it will loose pressure at a specific part of the five mile drive. Right after I pick my son up from school. It has completely stalled on me several times and other times it will go back up to around 3psi. Enough to get home. I have changed the filters, blown the lines out, tried removing the tank and cleaning it the best I could. Yesterday, it did it again. I had left the setup alone because I will replace it all when I put the mighty 396 Big Block in. But it made me made yesterday.

I got home and removed all of the fire departments mess. I then installed a Carter electric centrifigul pump that I had used on my '53 Studebacker street rod truck. I mounted the pump to the back of the underbed locker, inside the frame rail as high as I could get it with an angle drill. I now am getting 9-12 psi at any speed and my filters look very clean. I know, I have only driven 10 miles, but normally by this time the filters get a brownish appearance.

I pressure tested the inline pump and it seems to be putting out a constant 5-8 psi. The only thing I can think of is fuel vaporization or vapor lock. The pump was mounted pretty close to the exhaust manifold and was having to pull the fuel.

I just wanted to share this because that seems like a great place to put a pump. It is out of the way, protected from brush and such by the frame/bed/fuel tank and easily accessible for maintenance.

Hopefully that solves the problem...sounds like it should...good tip on the mounting, hanks for sharing that!!

I figured out where this was going long before you got there, man.

An old shade-tree mechanic trick to prevent vapor lock on systems prone to such , wa to apply a wooden clothespin to the metal line - it was supposed to act as a heat sink or something. I'd bet that the FD had the same prollem, and the clothepin was the fix for that, as opposed to fuel line clamp.

I'm just sayin'....

360fords in 67-72 pu were notorious for this.

when you moved the pump back by the tank you let the pump push fuel uphill versus trying to draw it uphill. electric fuel pumps were designed to push fuel and back there away from the heat you also eliminated vaper lock. I had the same problem with my pro streeter and the guys at holley told me this and it worked great for me and I never had another problem with it. the closer to the tank the better.

This is why so many vehicles including some M vehicles have the pump in the tank. M35's and M151&A1 have them in the tank...So did my M211 now that I think of it.