72 318 Fuel Pump Question

[Magnes]

My car (72 318) was starting and running good but yesterday I went out to move it and it wouldn't crank. I'm getting spark. I have some temporary clear fuel filters in place, one before the pump and one after. I checked them and they had a very small amount of fuel in them. The car wants to start but dies immediately (probably just fumes). So I put about 4 more gallons of gas in it, disconnected the coil and cranked it... Wasn't getting any fuel into the filters. Disconnected the filter before the pump and blew it out. It had a little junk in it but nothing plugging it up.

I attached my mity vac to the fuel line and used it to suck fuel through the line. It pulled fuel through easily needing less than 5 psi). So basically, I'm thinking it's got to be the fuel pump. So I call O'reillys and they order me one. I picked it up (pump is part number M23013)(also has 6866 as alt part number).

When I get it home, I pull the original pump and compare the 2. The arms on the pumps are quite different. The new pump has one nipple on the inlet side and a threaded port on the outlet side with no nipple. The old pump had 2 threaded ports with adapters and nipples threaded in place. I pulled out one of the adapters/nipple out of the old pump and it won't even thread into this new one....

At this point I don't even know if this is the right pump. Other than the mating surface (gasket area, where you bolt the pumps to the block) these 2 pumps have nothing in common. I looked on Rockauto and they are showing this to be the right pump.

Anyone have any knowledge on this? Should I just go find an adapter and nipple that will thread in this port on the new fuel pump? What about the differences in that arm?

 

[Cranky]

Small blocks have a long pump arm and big blocks have a short arm. The arms can look different but so long as the length is really close to the same, it should work and small blocks don't use a push rod so that won't be the problem. Also, mechanical pumps usually don't like a filter behind them. They pump better than they suck....

 

[69Bee]

One filter after the pump as Cranky said, and it matters not about nipple or threaded. If you need to make it work for your situation, just get the proper threaded adapters to hose.

 

[Magnes]

Thank you for the reply! I will remember that.

I don't know why I didn't think to pull the one off my parts car just to compare the pumps... But that's what I did here, and I think I figured it out.

The pump on the left is the one off my parts car (72 Sat Seb 318 car that has been inoperable since '83). The pump in the middle is the pump that came off my car (72 SSP 318) and was working up until recently. And the pump on the right is the new one.

Comparing the one that came off my car to the new one, they look completely different, BUT comparing the new one to the one off the parts car they look very similar.

I found a use-able fitting on the parts car which will allow me to make the new pump work.

So anyway, I just wanted to update this so you guys don't think I'm just flipping nuts... I sure thought I was for a while. But you can see the differences are quite substantial, hence my original concern.

Hopefully this thing will be drinking gas again in a bit.